when you downshift with manual transmission, are you burning more gas than not downshifting?

Question

downshifting causes the rpm's to increase- does this burn more gas than coasting without downshifting?

Answer 1

Actually you use less on a fuel injected car downshifting because the injectors turn off until the engine speed drops back down to 1200rpm and then begin pulsing again.

However, on a carbureted car, it will use "slightly" more gas.

ADDED:
Apparently these people didn't notice the fact you are "DOWNSHIFTING"

ADDED#2 "GSD pal" That's where the throttle position sensor comes into play. Press the gas pedal, re initiate the injectors.

Answer 2

If you shut the injectors off while downshifting then how are you supposed to accelerate the engine? Let us say that I am cruising on the highway at 60mph in 5th gear. Another car now gets in front of me and is now going slower. I downshift into 4th gear to accelerate past the other car. If the computer were to shut off the injectors, I would be going nowhere fast. There are a number of situations where the computer will de-energize the injectors. If you cause an "increase" in engine speed then this is not one of those times.

Answer 3

I am going to answer your questions in sections. 1. The easiest way that I found to downshift to a stop is this...When you are coming to a stop, lets say you are in 4th gear, push in the clutch and hold it in, downshift into 3rd still holding the clutch in. Its exactly the same as putting the car into neutral. Downshift into 2nd and then into 1st at a stop. DO NOT shift into 1st gear until you are fully stopped at zero mph. The reason why I say hold the clutch in the entire time is because, like I said earlier, it s like putting the car into neutral and you could basically coast to a stop instead of doing the clutch, downshift, release, repeat. It's much simpler, but not very many people do it. I do it, but no one taught me, I just thought it was easier than any other way. So basically as you said it, clutch downshift all the way to 1. 2. It is true that you should never, ever downshift into 1st gear UNLESS you are at a complete stop. Even if you are going 4mph, keep it in 2nd gear. 3. A fast start. If you have ever seen the movie The Fast and the Furious or any other racing movie. Just watch what they do and that's how to get off to a fast start. Just hold the clutch in, rev up some RPMs, just like taking off from a dead stop except do it faster and floor the gas and drop the clutch. 4. The passing and best way to speed. Passing someone is just like doing it in any other car. Not hard, don't know why that had to be asked. Anyways, the speeding thing, I wouldn't recommend it because if you get caught, depending how much over the limit you were going, major points on your license resulting in a suspension of license. So don't do it. Be safe.

Answer 4

If the rpm's are too high then yes you are burning a lot more fuel but if they get too low, such as if you are lagging the motor at 1000rpm then it is also burning a lot by running rich. The best mph are achieved by running it where the engine is most "comfortable" and the air fuel ratio is at its best mpg. With in my civic I will get better gas milage if I DON'T use 5th gear in town because I'm not going fast enough for the motor to generate enough power to effectively move the car and it is compensating by delivering a lot of fuel. It is the opposite if I am on the highway.

Answer 5

I would think so. Anytime an engine is turning more RPM's, I would think that it is firing more often and therefore, consuming more gas. Although, it probably isn't alot since downshifting doesn't happen for long durations like driving at higher RPM's.

Answer 6

Yes, Fuel consumption increases with lower gears, where you are using more friction (teeth on the gears). Most instruction manuals suggest you move to higher gears as soon as possible. This reduces wear and tear and increases mileage.

You can tell when fuel consumption goes up because the engine makes more noise. Breaking hard and frequently changing gears is also inefficient and burns gas, so slow down and 'cruise to a stop'.

Answer 7

sure it does, anytime you increase your RPM's your using more gas.

Answer 8

my friend says no because the throttle is closed so there's no fuel going thru it.

Answer 9

any time your rpms are high you are burnin more gas.