Manual transmission/shifting question

[SilverFeniks]

Hi;

I just bought my car this summer, and had never driven a manual before. I have shifting down fine, but had a question about shifting for optimal gas mileage and power.

Some stats I found say my car (2.0 SOHC) has 115hp @ 5400rpm and 122 torque @ 3200rpm.
I usually shift at about 3000 rpm, and was wondering when I should shift for best gas mileage.
Also, I know my car is slow, but if I felt the need to drive it as fast as possible some time, is it best to run it up to 5400rpm in each gear?

Any help or advice is appreciated, thanks !

[SilverFeniks]

anyone ??

[Pringles]

Don't know about drivin for optimal gas mileage but for maximum performance yes you should shift just before the rev-limiter kicks in, and with enough practise you can make lighting fast shifts that will help make your car seem pretty damn quick.

[victimizati0n]

LOL! I dont think he would have a rev limiter in it, unless your talking about something other than drag racing one's.

My lawnmower kinda has one, after it get's so high, it will kick back, and I have to adjust the RPM.

[Pringles]

Every car has one.

[BullShifter]

Originally Posted by Pringles

Every car has one.

Thats not true. MOST every car has one

shifting at 3000rpm should be good, you drive a 4-banger does gas mileage really matter? There are so many things that effect gas mileage beisdes accleration. For optimal shift at high RPM(before rev-limiter)you should feel the power drop-off before redline - shift at that time. Nice smooth quick shift - there is no reason to slam gears even though it seems fun.

[SaabJohan]

Accelerate hard on a low gear until you have reach the speed you want, then shift to the highest gear the engine runs well on. This means that you don't have to go through all gears.

If you want low gas mileage you don't need to be so careful when you shift, just accelerate fast and then keep you speed. If you need to brake, try using the engine. If you also want low emissions don't go over half throttle and around 3000 rpm (also depends on what engine you have).

For maximum performance you should go through all gears since that will give the highest mean power but it would also be easier on the gearbox than skipping a few gears.

[SilverFeniks]

thanks for the help everyone

[Pringles]

If you need to brake, try using the engine? This is bad.

[BullShifter]

Brakes are cheapier than clutches, transmissions, engines . . .

[Pringles]

So what cars don't have a rev-limiter? Really old ones? And what happens if you don't back off? BANG?

[SilverFeniks]

I think you blow your gears or something if you go too fast in a particular gear ... my friend said he went 70 in 3rd or something and lost a gear, lol.

later he totalled his car idiot

[SaabJohan]

The clutch should not be used to brake with, the engine is however an excellent brake. Newer fuel injected engines also shut off the fuel when the engine is used to brake and this can save a lot of fuel. This will also help to cool down the combustion chambers.

The engine will not break because it's used to brake the car, but if one change to the wrong gear it can (too high rpm), but this can happend both under upshift and downshift. If it happends it's usually the conrods that break and go through the engine block or the valves that hits the pistons.

[SaabJohan]

Originally Posted by SilverFeniks

I think you blow your gears or something if you go too fast in a particular gear ... my friend said he went 70 in 3rd or something and lost a gear, lol.

later he totalled his car idiot

No, you won't blow your gears. Gears usually fail because the torque or temperature is too high not because of high speed.


By the way... some cars can do 70 in 1st gear.

[Pringles]

Originally Posted by SaabJohan

The clutch should not be used to brake with, the engine is however an excellent brake. Newer fuel injected engines also shut off the fuel when the engine is used to brake and this can save a lot of fuel. This will also help to cool down the combustion chambers.

How exactly would you use the clutch as a brake in the first place?

You should NOT use the engine as a brake. For one thing, you will be wearing out your clutch much sooner if you do. God invented brakes for braking so why the hell would you use the engine as a brake.
You're crazy.