2010 Lexus RX350 - Doesn't detect Gas when small amount?

[deal_with_singh]

Hey guys,

To anyone who has this car, or has any idea what the issue might be, or if it is normal....

Tried googling this but didn't get any results.

Basically, this has happened to me a few times where when my gas is pretty much empty (car reads 5-10km left) and I fill up with $10-15, the needle doesn't move, and on my cars display, it still shows only 5-10km left at the start and actually goes down to 0.

Is this something normal? Is the Gas Station defrauding me somehow, where there is no gas thats being pumped into the car?

Is there something wrong with my car?

Reason I fill up with small amounts sometimes is I usually fill up at a costco and sometimes when I'm not able to, I just fill up in small amounts to be able to make it to one haha.

[Inphinity]

Well, how big is the tank and how much gas does $10-$15 get you based on your octane choice?

And is Costco gas really that much cheaper than it's competitors? o_o

[deal_with_singh]

It's a 75 Litre Tank, I typically put in 10 Liters of gas when not using Costco gas. I use regular 87 Octane when filling up from non-costco locations

When filling up at Costco, I use 91 Octane.

I save about 10 cents a litre using Costco's 91 Octane vs 91 Octane from a shell, petro, etc.

My car also shows averages: The total average from when I bought till now (has 60k km on it now) is 12.1 Litres per 100km

[1337rice]

Car display isn't accurate just so you know...it doesn't even matter what car you drive.

And why would you put 87 octane? So you can save a couple of bucks? Yet you drive a Lexus RX350? :facepalm:

[anhtuan]

Aren't you suppose to use 91+ Octane in that car? If you put in $10-15 these days you should be getting a bit more than 10 Litres, it takes a few mins for the gas meter to start reading the new gas sometimes. Atleast thats how it was in my old Infiniti.

[dassub]

Sounds like someone is using their parents car and putting in 10 bux worth of gas in the hopes that their parents will fill it up before they use it next.
Don't worry, we've all had those years ;)

[deal_with_singh]

Car display isn't accurate just so you know...it doesn't even matter what car you drive.

And why would you put 87 octane? So you can save a couple of bucks? Yet you drive a Lexus RX350? :facepalm:

Even if the display isn't accurate in terms of the kms....shouldn't the needle on the meter at least move?

As for 87 Octane...my dealership (Don Valley North Lexus) told me I should simply use 87 octane every other fill up to save money.


Aren't you suppose to use 91+ Octane in that car? If you put in $10-15 these days you should be getting a bit more than 10 Litres, it takes a few mins for the gas meter to start reading the new gas sometimes. Atleast thats how it was in my old Infiniti.


Sounds like someone is using their parents car and putting in 10 bux worth of gas in the hopes that their parents will fill it up before they use it next.
Don't worry, we've all had those years ;)

This is my own car, as I said, I fill it up with small amounts just so I can keep it running till I'm able to fill it up at a Costco. Saves about 10 bux a fill up.

[BCRCornet]

I can only comment based on what I have seen with my 2010 RX 350:
On the Multi Information Display in the centre of the instrument cluster, in "Cruising Range" mode, it counts down to 30 km or so (the lowest I've seen is 28 km), then the numbers disappear, to be replaced by the words "Low Fuel". I've never seen anything like 5 or 10 km range remaining.
If I put in less than a full fill-up when it shows "Low Fuel" or even some small number (e.g., 40) of km range left, the range updates to some appropriate number, e.g., 120 km range remaining. It does not still say "Low Fuel" or 40.
(BTW, I've read that even when it shows "Low Fuel", I've still got about 70 km range left.)
I only use premium-grade fuel. Reports I've read say that using regular grade fuel decreases mileage by about 10%, so you use 10% more fuel to go a particular distance compared to using premium grade. Since premium costs 10% more, there's no advantage to using regular grade.
Oh, and I use Costco gas when I can. However, the nearest Costco gas station is a 25 minute drive away, so getting there pretty much wipes out the savings.

[macnut]

As you can imagine, gas gauge methodology cannot really be a precise process. Gas slopping around in the tank every time you corner or brake, etc.

So there must be a lot of damping built in to the sender itself or the signal it sends to the instrument panel. Sounds like yours is over doing the damping though.

Might be because of sulphur deposits on the sender - a dose of concentrated Techron might help. But if it acts properly at the Full end, that may not be it.

As an aside, never a good idea to run that low. You will be picking up stuff at the bottom of the tank in the hope your filter can handle it.

And 12.1 L per 100km. isn't too good for an RX350 is it? Must be a lot of city driving. Hope you get more like 10.0 on a longer trip.

[azncapcom]

I've noticed the same issue on my ES350 before. If your light is on and you fill very little, sometimes the MID does not update. There is probably a sensor like every 1/3 of the tank or something(and the approx km reading is probably computer guessed based on how fast you are driving and how hard you are accelerating). However, the needle gauge should go up. Im not sure why your needle doesn't move up? I've seen my MID at 0km but my needle still showing 1/5 of a tank before.

Also with regards to the 87 vs 91 debate, its up to the consumer. New Lexus states that you can use 87. Older lexus (2011 and under) state you need 91. However, they have not changed the engine at all and it also corresponds to V6 camry and highlander engine. So many people have been using 87 and have not run into any problems. As for the better mileage on 91, that is debatable. Some do say you get better mileage, but most users on clublexus have gotten similiar mileage with regular vs premium.

[azncapcom]

12.1L / 100km should be pretty normal. I haven't checked my RX350's values but my ES350 is at 10.7L / 100km for 50/50 driving. The RX would be a bit more cause of the AWD and heavier.

[1337rice]

Aren't you suppose to use 91+ Octane in that car? If you put in $10-15 these days you should be getting a bit more than 10 Litres, it takes a few mins for the gas meter to start reading the new gas sometimes. Atleast thats how it was in my old Infiniti.

Where do you live? $10 doesn't even give you 10 litres anymore...not even 87 octane lol...

But seriously...$10-15 of gas is nothing nowadays. If your car has a 75 litre gas tank, and putting in 6-8 litres while expecting the needle to go up...well...it's not. The meter and the computer does not account for the fuel reserves which your $10 is "filling up".
It's bad to run on empty or near empty anyways. If you want to keep whining about why your car's fuel needle ain't going up, chances are, it'll probably won't go up AT ALL once your fuel pump dies :lol:

[macnut]

Just checked what Toyota says in the MID section of the Owners Manual:

When only a small amount of fuel is added to the tank, the display may not be updated.

The key word there is probably "may". It might update sometimes, not others. Or in some cars, not others. Or depends on how small the amount is.

I think this is fairly standard wording in many Owner's Manuals (at least for Japanese makes).

[deal_with_singh]

I can only comment based on what I have seen with my 2010 RX 350:
On the Multi Information Display in the centre of the instrument cluster, in "Cruising Range" mode, it counts down to 30 km or so (the lowest I've seen is 28 km), then the numbers disappear, to be replaced by the words "Low Fuel". I've never seen anything like 5 or 10 km range remaining.
If I put in less than a full fill-up when it shows "Low Fuel" or even some small number (e.g., 40) of km range left, the range updates to some appropriate number, e.g., 120 km range remaining. It does not still say "Low Fuel" or 40.
(BTW, I've read that even when it shows "Low Fuel", I've still got about 70 km range left.)
I only use premium-grade fuel. Reports I've read say that using regular grade fuel decreases mileage by about 10%, so you use 10% more fuel to go a particular distance compared to using premium grade. Since premium costs 10% more, there's no advantage to using regular grade.
Oh, and I use Costco gas when I can. However, the nearest Costco gas station is a 25 minute drive away, so getting there pretty much wipes out the savings.

After the 25km remaining mark, the display changes to "Low Fuel" but if you flick the switch and try to see something else, just simply go back to the KM remaining and you can see whats left.

I use premium whenever I can, but sometimes just put in regular. I use premium vs regular 2:1.


As you can imagine, gas gauge methodology cannot really be a precise process. Gas slopping around in the tank every time you corner or brake, etc.

So there must be a lot of damping built in to the sender itself or the signal it sends to the instrument panel. Sounds like yours is over doing the damping though.

Might be because of sulphur deposits on the sender - a dose of concentrated Techron might help. But if it acts properly at the Full end, that may not be it.

As an aside, never a good idea to run that low. You will be picking up stuff at the bottom of the tank in the hope your filter can handle it.

And 12.1 L per 100km. isn't too good for an RX350 is it? Must be a lot of city driving. Hope you get more like 10.0 on a longer trip.
See what bothers me, the other car I drive (family car) which is an 05 Camry, has never reacted this way. I've done $10 fill ups all the time in that one (typically when I know gas is gonna drop big, etc.) and I've never had issues where the needle doesn't move. But with my 2010 RX, neither the needle move or the number of kms.

To help it out, I even parked the car backwards on my downward sloping driveway to see if I can help it move the gas to the front over night (gas station I filled up at is approx 2km away from my house so shouldn't affect the amount). Next morning, the situation was still the saem where there was 0km on the display and the needle all the way to the "E"

As for the milage...I have the guide in front of me...it states:

EPA Fuel Economy Estimates: 11.6/8.2/10.1 L/100km (city/highway/combined)

My driving is pretty much split 50/50 between highways and city. Unless you count roads such as highway 7 or highway 27 a highway (I'm pretty much driving mostly on highway 7).

My most recent fill up averages have been between 11.2L/100km and 11.9L/100km. Current after filling up yesterday is 10.8L per 100km (but it will go up as I drive till I'm near the E)

The best I've gotten out of this car was 7.7L/100km on my drive down to NYC, gave me almost 700km on my full tank...typically lasts 550km on a good fill up, and as low as 450km in the winter when I average 14-15L/100km.


I've noticed the same issue on my ES350 before. If your light is on and you fill very little, sometimes the MID does not update. There is probably a sensor like every 1/3 of the tank or something(and the approx km reading is probably computer guessed based on how fast you are driving and how hard you are accelerating). However, the needle gauge should go up. Im not sure why your needle doesn't move up? I've seen my MID at 0km but my needle still showing 1/5 of a tank before.

Also with regards to the 87 vs 91 debate, its up to the consumer. New Lexus states that you can use 87. Older lexus (2011 and under) state you need 91. However, they have not changed the engine at all and it also corresponds to V6 camry and highlander engine. So many people have been using 87 and have not run into any problems. As for the better mileage on 91, that is debatable. Some do say you get better mileage, but most users on clublexus have gotten similiar mileage with regular vs premium.

Interesting...so in your opinion, the gas station I used (Shell on Highway 7 and Highway 27) was either ripping me off, or I should get my car checked out?

As for the milage with regular vs premium....here's my experience....

In the last 2 fill ups I had....the first one was Premium 91 octane, and the one right before my current fill up was a regular 87 Octane...here's my results....

Using the exact same route (from home to work) I get:
Fill up 1 (Premium 91 Octane) - 11.4L/100km, got about 560km out of the tank before I re filled
Fill up 2 (Regular 87 Octane) - 11.7L/100km, got about 540km out of the tank before I re filled.

Now I'm sure there's other factors involved such as traffic, idling time, number of red lights, and things like wind speed that could have influenced the milage, but these are the results I got.

[deal_with_singh]

Where do you live? $10 doesn't even give you 10 litres anymore...not even 87 octane lol...

But seriously...$10-15 of gas is nothing nowadays. If your car has a 75 litre gas tank, and putting in 6-8 litres while expecting the needle to go up...well...it's not. The meter and the computer does not account for the fuel reserves which your $10 is "filling up".
It's bad to run on empty or near empty anyways. If you want to keep whining about why your car's fuel needle ain't going up, chances are, it'll probably won't go up AT ALL once your fuel pump dies :lol:
IDK what you drive, but I can easily get a 100km out of those $10-15 lol...and that's about 3 round trips to and from work.

Also you're contradicting yourself. If the fuel meter and computer don't count the reserve, why would I be "filling up my reserve" if my display is still showing some km's left with my gas.


Just checked what Toyota says in the MID section of the Owners Manual:

When only a small amount of fuel is added to the tank, the display may not be updated.

The key word there is probably "may". It might update sometimes, not others. Or in some cars, not others. Or depends on how small the amount is.

I think this is fairly standard wording in many Owner's Manuals (at least for Japanese makes).

Interesting...so the MID display is fine I suppose, but the needle should at least move above the E?

[azncapcom]

I doubt it was the gas stations problem. You were probably on REALLY empty, that the little amount of gas you filled was not able to move the needle. Its like when you fill a complete tank, the needle will be over the full line but would stay there for a long time. So if you were to fill a few litres less than the maximum, your needle would still read over the full line but it would start decreasing faster.

a couple fill ups is not an accurate comparison. You would have to say at least 10 fill ups of the same grade in a row, and then another 10 fill ups of the other grade in a row, doing the same route at the same time etc.

also macnut is right about the reserves. When your MID says 0km it does not mean you really have 0km left. The MID does not account for your reserves. It probably works like 2 boxes, 1 big box at the top and a small box under the big box. The sensor would show 0km when the big box is empty.

You can somewhat account for how much reserve you have. Say your tank is 75 litres, and you fill up when your MID is at 0km (after the light has been on for a while) You will not end up filling a complete 75 Litres. I assume it will be less than 70 litres you will be filling up.

My tank is 70 litres and i fill up about 60 litres when the light comes on. The most i've ever filled was 64 litres with the MID reading 0km.

[anhtuan]

Where do you live? $10 doesn't even give you 10 litres anymore...not even 87 octane lol...

But seriously...$10-15 of gas is nothing nowadays. If your car has a 75 litre gas tank, and putting in 6-8 litres while expecting the needle to go up...well...it's not. The meter and the computer does not account for the fuel reserves which your $10 is "filling up".
It's bad to run on empty or near empty anyways. If you want to keep whining about why your car's fuel needle ain't going up, chances are, it'll probably won't go up AT ALL once your fuel pump dies :lol:

He said $10-$15. So assumming gas is $1.28/L he could get more than 10 litres with $15...

[spike1128]

He said $10-$15. So assumming gas is $1.28/L he could get more than 10 litres with $15...

What can we say? The OP is a real BUDGET BALLER. He putting like less than 10L if he put in 10 bucks. I suggest him to drive a Corola instead. Instead of saying that he is not filling enough to move the needle, he blames the SUV/sensor. Epic fail! Didn't the OP know that fuel sensors aren't accurate? Everyone who is riding a motocycle with a gauge would know the gauge say you got 10% left, but in reality he is running on empty (don't trust the gauge).

[RCGA]

I don't understand the point of just putting in 10L of gas. Isn't that harder on the engine if you're on empty half the time (something about sluge?)?

[mr_raider]

Car display isn't accurate just so you know...it doesn't even matter what car you drive.

And why would you put 87 octane? So you can save a couple of bucks? Yet you drive a Lexus RX350? :facepalm:

The RX and ES are calibrated to run on 87. The IS needs premium.

[GunnerX]

What can we say? The OP is a real BUDGET BALLER. He putting like less than 10L if he put in 10 bucks. I suggest him to drive a Corola instead. Instead of saying that he is not filling enough to move the needle, he blames the SUV/sensor. Epic fail! Didn't the OP know that fuel sensors aren't accurate? Everyone who is riding a motocycle with a gauge would know the gauge say you got 10% left, but in reality he is running on empty (don't trust the gauge).


I don't understand the point of just putting in 10L of gas. Isn't that harder on the engine if you're on empty half the time (something about sluge?)?

Did you guys even read what the OP is doing? When he's near empty and not close to a Costco gas station where he usually fills up, he goes to the nearest gas station just to put in a bit so he can go to Costo and fill all the way up. What's wrong with that?

However, most cars nowadays have a BIG reserve setup. The Fuel gauge actually hits the Empty mark very early on. On some cars, there's as much as 30L in the reserves. I'm thinking this is what Toyota does with the new cars. So filling up 10L still doesn't bring the fuel above the reserve so the needle will still stay on the E and not move up.

[RCGA]

Did you guys even read what the OP is doing? When he's near empty and not close to a Costco gas station where he usually fills up, he goes to the nearest gas station just to put in a bit so he can go to Costo and fill all the way up. What's wrong with that?


I read it, but unless you're passing Costco on a regular basis and take the time to wait in the lines, I don't see the point. You can all it being frugal, but that's a stretch when you're trying to save $5/month on gas, yet own a $50k luxury SUV

[spike1128]

Did you guys even read what the OP is doing? When he's near empty and not close to a Costco gas station where he usually fills up, he goes to the nearest gas station just to put in a bit so he can go to Costo and fill all the way up. What's wrong with that?

However, most cars nowadays have a BIG reserve setup. The Fuel gauge actually hits the Empty mark very early on. On some cars, there's as much as 30L in the reserves. I'm thinking this is what Toyota does with the new cars. So filling up 10L still doesn't bring the fuel above the reserve so the needle will still stay on the E and not move up.

What's wrong with it? He is trying to save a few cent extra by putting in 10L instead of 20L. His tank is 70L, so he is always running on 1/3 of the gas he is suppose to. Of course he doesn't care if his car's life span is getting cut. Not to mention his gas evaporating in the tank.

Instead of him running near empty to go fill up at Costco, he should go fill up when he is 1/4 or 1/2 empty. Not to mention that I said he is a budget baller, he has $ to be driving around in a Rexus, but no want to pay gas $ in other station. I thought ballers don't care if they lose a few bucks filling up at other stations, I guess I am wrong.

[GunnerX]

So people who own nice cars have to be Ballers?? Bahahahahaha!!!!!

[spike1128]

So people who own nice cars have to be Ballers?? Bahahahahaha!!!!!

Yes, that's the first rule in RFD. A lot of millionaires spend their time on RFD all the time. Didn't you read the other poster's sigs?

One requirement: All RFD makes more than 100k a year
Two: All who drive luxury cars are ballers
Three: If you have 100k in your bank account, you are HIGH NET WORTH!

[Badman]

the lexus gas tank was not designed to care about only $10 in gas. Only meant for ballers who can fill up gas in full amounts.

[mrperfect]

It happens to me to as well when filling small amounts of Petrol, however after driving for a while the meter does climb up a little bit so I think its because of a tank shape/fumes etc. By the way filling smaller amounts of gas doesnt make anybody cheap, people have their own reasons, and probably OP fills up in the US like me and only fills it up here in emergency?

[ichpen]

Hey guys,

To anyone who has this car, or has any idea what the issue might be, or if it is normal....

Tried googling this but didn't get any results.

Basically, this has happened to me a few times where when my gas is pretty much empty (car reads 5-10km left) and I fill up with $10-15, the needle doesn't move, and on my cars display, it still shows only 5-10km left at the start and actually goes down to 0.

Is this something normal? Is the Gas Station defrauding me somehow, where there is no gas thats being pumped into the car?

Is there something wrong with my car?

Reason I fill up with small amounts sometimes is I usually fill up at a costco and sometimes when I'm not able to, I just fill up in small amounts to be able to make it to one haha.

Probably a fuel sender feature. All cars are different but when it comes to low fuel situations they all act the same. Fuel range calculations are blanked out or ignored. It's more of a safety feature than a defect.

If the gas station was defrauding you you'd be running out of gas all over the place. As a general rule of thumb do not have faith in fuel range calculations when you're running low, most err on the side of caution and will advise you to fill up.

P.S. If you car doesn't recommend or require premium gas you're wasting your money filling up 91.

[DDHLeigh]

opps, sorry rx is reg gas.

[BCRCornet]

opps, sorry rx is reg gas.

For the 2010 and 2011 model years, the recommended fuel is premium grade.

For 2012 (and I presume 2013), the recommended fuel is regular grade.

[deal_with_singh]

I read it, but unless you're passing Costco on a regular basis and take the time to wait in the lines, I don't see the point. You can all it being frugal, but that's a stretch when you're trying to save $5/month on gas, yet own a $50k luxury SUV
I drive down by the Costco on Highway 7 and Weston on almost a daily basis on my way to and from work. I need to fill up once a week. So yes, $10 a week, 4 times a month, or 52 times a year does add up. Savings of almost $520 a year. Tips on filling up at costco...come near closing time (closes at 9:30, come around 920, and you will find the pumps empty)


It happens to me to as well when filling small amounts of Petrol, however after driving for a while the meter does climb up a little bit so I think its because of a tank shape/fumes etc. By the way filling smaller amounts of gas doesnt make anybody cheap, people have their own reasons, and probably OP fills up in the US like me and only fills it up here in emergency?
See that's what I'm worried about though...I drove around about 20-30km before getting to a costco for a fill up and still didn't move. And no don't fill up in the states, just at a costco where gas is typically 10-12 cents cheaper for the 91 octane.


Probably a fuel sender feature. All cars are different but when it comes to low fuel situations they all act the same. Fuel range calculations are blanked out or ignored. It's more of a safety feature than a defect.

If the gas station was defrauding you you'd be running out of gas all over the place. As a general rule of thumb do not have faith in fuel range calculations when you're running low, most err on the side of caution and will advise you to fill up.

P.S. If you car doesn't recommend or require premium gas you're wasting your money filling up 91.

Actually, my car manual and a sticker in the fuel hatch both state "Only use 91 Octane" or something like that, but my dealer said it was fine to use 87 octane, and in fact thats what they do. Also many threads across the net claim the RX engine is similar to that of a V6 Camry and does not require it.

[ichpen]

I drive down by the Costco on Highway 7 and Weston on almost a daily basis on my way to and from work. I need to fill up once a week. So yes, $10 a week, 4 times a month, or 52 times a year does add up. Savings of almost $520 a year. Tips on filling up at costco...come near closing time (closes at 9:30, come around 920, and you will find the pumps empty)


See that's what I'm worried about though...I drove around about 20-30km before getting to a costco for a fill up and still didn't move. And no don't fill up in the states, just at a costco where gas is typically 10-12 cents cheaper for the 91 octane.



Actually, my car manual and a sticker in the fuel hatch both state "Only use 91 Octane" or something like that, but my dealer said it was fine to use 87 octane, and in fact thats what they do. Also many threads across the net claim the RX engine is similar to that of a V6 Camry and does not require it.

It's not about the engine, it's about the computer commanding your timing. I made a big thread on the topic so search of it but bottom line is I would not recommend you run regular then. Just because you can get away with it doesn't mean it's good for your car.

[azncapcom]

It's not about the engine, it's about the computer commanding your timing. I made a big thread on the topic so search of it but bottom line is I would not recommend you run regular then. Just because you can get away with it doesn't mean it's good for your car.

the engine is the exact same. Yes the ECU is different. However, the ECU can adjust to compensate for regular gas. So pretty much it can act like the ECU for a camry. Some argue that the ECU can adjust for lexus to use regular gas but ecu on toyota cannot adjust to benefit from premium gas. Either way using regular gas will not harm you car. It may or may not be more beneficial in terms of mileage wise but in terms of damage, there is none. This has been debated for a decade already.

[Heero01]

the engine is the exact same. Yes the ECU is different. However, the ECU can adjust to compensate for regular gas. So pretty much it can act like the ECU for a camry. Some argue that the ECU can adjust for lexus to use regular gas but ecu on toyota cannot adjust to benefit from premium gas. Either way using regular gas will not harm you car. It may or may not be more beneficial in terms of mileage wise but in terms of damage, there is none. This has been debated for a decade already.
LOL... please stop spreading non sense like this around. Have you ever driven a car (that calls for premium) on regular? You will get engine knock if you use regular gas in a high compression engine - which WILL damage your car. Dealerships say to use regular instead of premium because premium gas prices scare off potential car buyers/leasers who cannot really afford the car.

BTW: Here is the first article thing I found on google related to premium gas in cars:

“The octane number is a measure of the auto ignition properties of the fuel. A higher octane number means that the fuel is less susceptible to knocking,” says University of Alberta engineering professor Bob Koch. “It’s not a marketing gimmick. If it’s recommended by the manufacturer, it’s needed for your engine.”

http://www.theglobeandmail.com/globe-drive/car-tips/do-i-really-need-to-use-premium-fuel-in-my-premium-suv/article4102182/

[ichpen]

the engine is the exact same. Yes the ECU is different. However, the ECU can adjust to compensate for regular gas. So pretty much it can act like the ECU for a camry. Some argue that the ECU can adjust for lexus to use regular gas but ecu on toyota cannot adjust to benefit from premium gas. Either way using regular gas will not harm you car. It may or may not be more beneficial in terms of mileage wise but in terms of damage, there is none. This has been debated for a decade already.

Yes of course it can adapt otherwise you'd have some major catastrophes. Point is reduced performance and mileage so benefits may not be as bountiful. In addition you are introducing more knock into your motor until your ECU adapts especially if you're switching back and forth between grades. Long term not a good idea but feel free to debate away.

Running regular on highly strung motors especially FI is particularly detrimental even with timing adjustments and will most definitely lead to a shortened lifespan for parts of your motor.

Even if you're not car savvy please follow your manufacturer's manual as the bare minimum for vehicle maintenance and ownership. You pick, a manufacturer that has invested thousands of hours of R&D into your product vs a guy named Bob who posted that running regular is just dandy on your favourite forum.

[azncapcom]

LOL... please stop spreading non sense like this around. Have you ever driven a car (that calls for premium) on regular? You will get engine knock if you use regular gas in a high compression engine - which WILL damage your car. Dealerships say to use regular instead of premium because premium gas prices scare off potential car buyers/leasers who cannot really afford the car.

BTW: Here is the first article thing I found on google related to premium gas in cars:

“The octane number is a measure of the auto ignition properties of the fuel. A higher octane number means that the fuel is less susceptible to knocking,” says University of Alberta engineering professor Bob Koch. “It’s not a marketing gimmick. If it’s recommended by the manufacturer, it’s needed for your engine.”

http://www.theglobeandmail.com/globe-drive/car-tips/do-i-really-need-to-use-premium-fuel-in-my-premium-suv/article4102182/

Yes I have 2 lexus's at home and they both call for premium. And no it is not a high compression ratio. it is 10.5 to 1 which also uses the EXACT same motor as the v6 camry and highlander. The only thing different would be the ECU. You say its not a marketing gimmick but people have taken it up with lexus themselves and went far into the upper levels of the company and was not given a straight answer when showing the facts of the engine and all the specifications. Yes i completely understand how most cars that have high compression ratio WILL require premium. However, i am only referring to one case in which is lexus because they are using the EXACT same motor as the toyota ones that require regular only. And its funny how their new models have switched over to regular gas in the owners manual now without changing the motors or anything. If your argument is that they changed the ECU for the newer models to "compensate" for regular gas, then the older ECU's can EASILY be flashed to compensate as well. But nobody has done this and no companies even bother developing this because there is no need as the old ECU does it just fine.

I have driven Acuras as well and you DO feel a huge difference driving with premium fuel vs regular fuel. But in the case of lexus, there is no benefit of running premium at all.


Yes of course it can adapt otherwise you'd have some major catastrophes. Point is reduced performance and mileage so benefits may not be as bountiful. In addition you are introducing more knock into your motor until your ECU adapts especially if you're switching back and forth between grades. Long term not a good idea but feel free to debate away.

Running regular on highly strung motors especially FI is particularly detrimental even with timing adjustments and will most definitely lead to a shortened lifespan for parts of your motor.

Even if you're not car savvy please follow your manufacturer's manual as the bare minimum for vehicle maintenance and ownership. You pick, a manufacturer that has invested thousands of hours of R&D into your product vs a guy named Bob who posted that running regular is just dandy on your favourite forum.

Actually I am pretty car savvy, I do most of my repairs on my car myself. Including oil changes, transmission fluid changes, brakes, suspension, serpinetine belt, etc.