what waste more gas....?

[lumlum1013]

as stated in the topic,

say if i'm drivin' @ 60km/h, if i'm @ 5th gear, i'm at around 1900rpm, and my engine loading is around 60ish%

but if i'm @ 4th gear, i'm @ around 3600rpm, and my engine loading is around 25%......

so wat waste more gas?

engine loading vs rpm

(engine loading % measurements are indicated by the scangauge, and no these numbers were not under turbo boost)

[Whitedart]

driving @ High gears, low rpm, mid-high engine loading over 50%
driving @ Low Gears, High rpm, typical engine loading around 20%-30%

I don't understand you poll.

Driving in higher gear with lower rpm will use less fuel in almost all situations.

[bobby5]

Doing low engine speed in high gear and on >50% loading might increase wear on the engine/tranny.
Not sure if the gas saved is worth it.

[seftonm]

If you have a scangauge, why not just look at the instantaneous fuel consumption? That will give a better answer than anybody on a forum can. In almost all cases, lower rpm for the same speed means lower fuel consumption. 1900rpm is pretty close to the sweet spot for most engines.

[xtracrispy123]

lower RPM will result in lower frictional losses due to slower rotational speeds.

Considering that most transmissions suck away like 20hp, making that thing spin slower would be a good thing.

[Rekognize]

Correct me if I'm wrong but I think the faster you get to the highest gear means you cover more distance per RPM.

With gas prices these days, I always granny-shift at 2k rpm

[M-e-X-x]

Correct me if I'm wrong but I think the faster you get to the highest gear means you cover more distance per RPM.

With gas prices these days, I always granny-shift at 2k rpm

probably not good for the tranny shifting so early... starting off from a standstill sure, but going thru gears i dunno...

[dgmorr]

if you are so concerned, get a vacuum gauge and keep it constant.

[ES_Revenge]

as stated in the topic,

say if i'm drivin' @ 60km/h, if i'm @ 5th gear, i'm at around 1900rpm, and my engine loading is around 60ish%

but if i'm @ 4th gear, i'm @ around 3600rpm, and my engine loading is around 25%......

so wat waste more gas?

engine loading vs rpm

(engine loading % measurements are indicated by the scangauge, and no these numbers were not under turbo boost)

I accidentally clicked the wrong option on the poll, I was wondering why so many people clicked the second one and then I realised you weren't asking which one saves more gas but which wastes more gas, lol.

Though we could get into they why and wherefore of fuel burning to put it quite simply, if cars used more fuel with higher gearing, they wouldn't be made with those gears to start with. I.e. They wouldn't make cars with a 5th, 6th, or 7th gear at all if the higher gears didn't increase fuel economy/waste less gas.

Taller/numerically lower gear ratios and large throttle openings (100% open throttle is best) will get you the most fuel economy, with any gasoline internal combustion engine. Since having gearing in a traditional transmission to cruise at highway speed with a wide open throttle is impracical, they invented the CVT