hello fellas

tC is my first manual car, and I am still in a learning process to get used to it. I have couple questions for experienced M/T drivers.

1. Is it ok to place gear at neutral when i cruise down a hill? On my daily drive to work, there is a downhill that streches out for about 2 miles, and i place my gear at neutral b/c i thought it's a great way to save gas. But is it really true?

2. let say i am crusing at 40mi/h. which gear is the most proper for this speed? What i mean by this is that if i put the gear at 4th, rpm runs at 2800, and at 5th, it runs at 2200. With my limited knowlege, I thought that the lower the rpm is at, the more gas i save. But, is that really true? I realized, of course, answers to the question totally depends on situations, but let's just say that i do not need a sudden acceleration or anything like that.

Please let me know guys
Thanks

 

1st 0-15
2nd 15-25
3rd 25-40
4th 40-45
5th 45-


is what the manual(haha) says in order to get the best gas milege(milage?).

 

1. It should be fine, but if you need to accelerate in a emegency type situation you might be in trouble. But I would probably do the same thing.

2. At 40mi/h I am almost always in 4th gear, however if I am having some fun I would be in third. Third gear at 35-40 mi/h has some really nice kick to it. :D

 

I put it in 5th at 40+ usually when it's just a relaxed drive on a country road with nobody to pass...

 

2 miles in neutral isn't going to save you that much gas, your supposed to put it in a lower gear like 4th or maybe even 3rd depending on the decline of the hill, that way you can keep control of your speed without using the brakes.

 

If you are going downhill and don't need to apply gas, then whether or not your in gear doesn't effect your gas consumption. Just like the heated discussion about shifting to neut. in order to stop ended, the car's gas usage isn't dependant on the RPM of your motor, rather the throttle your applying. If you are off the throttle (throttle at 0%), you will be using the same amount of gas as if you were idling. Try to stay in gear so that if something happens you are able to speed up/turn with better traction.

 

I've got some questions about this - I've driven manual for several years, but never gotten a clear answer about this one. When you're in gear going down a hill, your engine is cycling a lot faster than idle - say 3k RPM vs. 1k. Every time the engine turns, everything is linked, right? So there is a combustion process that burns gas every time around, right? So if you were off the throttle, you would presumably be burning a very small amount of gas every revolution, but 3k is still more than 1k. When you are on the throttle, i'd guess the computer pumps a lot more gas and air into the cylinders, right? That makes sense to me. I just don't understand how an engine turning at 3k RPMs can use as little gas as 1k.

 

before the engine breaking arguement starts again... here's the last one

https://www.scionlife.com/forums/viewtopic.php?t=23539

 

i think the ecu just turns off the injectors as long as you're in a low enough gear and not applying throttle since the grade of the hill will be turning the engine. therefore you use no gas when going down a hill. it is much better to leave the car in gear both for safety and gas mileage.