Hello everyone.

I have seen post where people claim that at high RPMs the car consume a lot of fuel. I also heard someone said that fuel consumption is closely related to driving habit.

Now I feel unless someone want to enter the high way and be driving at 80km/hr then you can be driving at 2000 - 25000 RPM. To be moving at 120km/hr to 140km/hr one will be doing it at higher RPMs say 3500-4000.

Please I need gurus in the house to help me understand the relationship between fuel economy, RPM and possibly the size of the engine.

All contributions will be highly appreciated.

Idealy rpm should be directly proportional to fuel consumption, ie at stand still, but gearing differential changes the physics while in motion, a lower sufficient rpm at idling is better than a higher one, all things bn equal

Idealy rpm should be directly proportional to fuel consumption, ie at stand still, but gearing differential changes the physics while in motion, a lower sufficient rpm at idling is better than a higher one, all things bn equal.

vertueptime:
Idealy rpm should be directly proportional to fuel consumption, ie at stand still, but gearing differential changes the physics while in motion, a lower sufficient rpm at idling is better than a higher one, all things bn equal.

Clap for yourself Sir


Now read what you just wrote....Do you understand it?


Instead of you to simply say "the higher the rpm, the higher the fuel consumption" and go and sit down, you are looking for who to give migraine with disjointed vocab

buygala:


Clap for yourself Sir


Now read what you just wrote....Do you understand it?


Instead of you to simply say "the higher the rpm, the higher the fuel consumption" and go and sit down, you are looking for who to give migraine with disjointed vocab

In my modest opinion i broke it down to dummy level for easier comprehension, let me not start with u this evening, allow me to jejely rest in my quarantine

Lower rpm + higher gear = best fuel consumption.

ping2ping:
Hello everyone.

I have seen post where people claim that at high RPMs the car consume a lot of fuel. I also heard someone said that fuel consumption is closely related to driving habit.

Now I feel unless someone want to enter the high way and be driving at 80km/hr then you can be driving at 2000 - 25000 RPM. To be moving at 120km/hr to 140km/hr one will be doing it at higher RPMs say 3500-4000.

Please I need gurus in the house to help me understand the relationship between fuel economy, RPM and possibly the size of the engine.

All contributions will be highly appreciated.

Now this depends on the engine, powerband, and gearing. I have a car with over 300hp, and I can be doing 120km/hr at just about 2200 rpm.

HeavenlyBang:
Lower rpm + higher gear = best fuel consumption.



Now this depends on the engine, powerband, and gearing. I have a car with over 300hp, and I can be doing 120km/hr at just about 2200 rpm.

You got the Acura?

9icetoo:

You got the Acura?

No. My G makes 306 HP.

HeavenlyBang:


No. My G makes 306 HP.

Cool.

9icetoo:

Cool.

E still dey the agenda, though. Still going through my options. But it's looking the most likely right now.

HeavenlyBang:


E still dey the agenda, though. Still going through my options. But it's looking the most likely right now.

If you buy it in Lagos, holla me make I come touch am small.

9icetoo:

If you buy it in Lagos, holla me make I come touch am small.

Sure thing, chief.

HeavenlyBang:
Lower rpm + higher gear = best fuel consumption.



Now this depends on the engine, powerband, and gearing. I have a car with over 300hp, and I can be doing 120km/hr at just about 2200 rpm.

Please can explain more the bolded part of the sentence?

ping2ping:


Please can explain more the bolded part of the sentence?

Depends on the engine simply means a V8 can do 120km/h at 1500rpm, a V6 can do 120km/h at 2500rpm and a I4 would do 120km/h at 4000rpm also depends on the engine volume but I have cars with the 3 engines and I know there capability

Powerband is the energy output (torque) dished out by an engine in conjunction with the gear eg a corolla with 1.6L engine would have a different power band at gear 2 to a 1.8L engine corolla of same year.

Please this are just layman's definition not a professor of physics or a gurus definition if I am wrong please endeavor to correct me and move on I don't want trouble this week.

it is true that higher rpm uses more fuel. the engine speed, which is what is represented by rpm, changes according to how much fuel you're feeding the engine through your throttle input. more fuel = more engine speed and less fuel = less engine speed. so a higher rpm will require more fuel than a lower one.

if your car is not moving, the most fuel efficient rpm is 0rpm. however once you engage the gearbox and start to move it's a whole other ball game.

the best mileage you want now is a combination of lower rpm and higher speed. e.g. 60km/h at 2000rpm is less efficient than 100km/h at the same 2000rpm. however this is only up to a certain point beyond which the higher speed doesn't come with additional fuel efficiency. so even though 100km/h at 2000rpm is more efficient than 60km/h at the same rpm, 200km/h at 4000rpm is less efficient than 100km/h at 2000rpm. there is plenty mathematics involved in calculating the most fuel efficient rpm/car speed combination but for most cars i've heard that it's around 100km/h at 2000rpm.

the engine size determines the exact rpm/car speed combination for ideal fuel efficiency for each car. as others have said, the more powerful the engine is, the faster it can go at any given rpm compared to a less powerful car, assuming both are in the same gear. so in gear 5 at 2000rpm, an i4 might be at 100km/h while a v6 will be at 110km/h. but this doesn't mean the v6 is a more fuel efficient engine o. all other things being equal, the v6 will use more fuel at that rpm. same goes for a v8 and the rest.

so it's true that fuel consumption is related to driving habit. it also depends on if you're driving in the city or highway. for city, if you tend to drive at higher rpms in lower gears or you just generally drive at lower speed like <50km/h you'll end up using more fuel than someone who does the opposite. the same is true for highway except that going too fast around >130km/h will also cost you more fuel.