chevy cobalt 08

Now with manual you can skip gears BUT does this hurt or help MPG? I usually do 1 2 4 (some times 5 depends on the road and traffic) and completely miss 3 cause it's too short of a gear. But that's fine right?

Joeyavhu

It will hurt if you have to raise the RPMS above 2.5K or 3K to shift, and it will hurt if when you shift, the engine bogs.
If it does neither, then it wont effect it.

EXsoccer1921

iTrader: (14)

yeah if you're going around 35mph when shifting out of second, raide the rpms to about 4500-4700 and go into 4th. i do it too

chevy cobalt 08

I never shift past 2.5k but if I do 1 3 instead of 1 2 I don't have enough power and it bogs pretty bad. but 1 2 4 there slight bog but it's not that bad but that couldn't really hurt mpg that much could it?

Joeyavhu

No, it really wont make a noticeable impact, maybe a tiny little bit. It doesnt take much to get this car not to bog, so it cant use that much fuel.

EXsoccer1921

iTrader: (14)

well you have the 2.4L tho don't you, i'm sc so i'm not sure what yours would do. still shouldn't be that big of a deal tho

chris88z24

I shift 1 gear at a time. Even if i'm only in that gear for a few seconds. It keeps the motor in it's powerband. Just becuase you are revving high doesn't necessarily mean you are using more gas. Ex, if you are at 5500rpms but your foot is off the gas, you are getting 99MPG essentially. Whereas if you're at 1200RPMS and you are at WOT, you are getting probably 5MPG lol. It's better for your syncros too.

chevy cobalt 08

hmm... so your saying if I downshifted from 4th to 2nd and say its revving at say 3.5k and my foots off the gas, that reving at that high rpm isn't using more gas? I was always afraid it was and would break harder to get down to under 2k quicker now I'm a bit relieved. =P

chris88z24

LOL nah man, if you're foot isn't on the gas your injectors aren't pouring any fuel into the cylinders (unless you are idling, of course). Engine braking FTW! I go down a hill to work everyday that's at least a 30-45 degree incline, I am in 2nd and at about 4k RPMs the whole ride down. I always get looks from the business people walking around as my car is rumbling and backfiring down the entire hill haha, it sounds really mean echoing off all the office buildings and such. If I were to reset my fuel econ as I was doing that it would go to 99.9MPG. lol

You use more gas throwing the car into N and coasting to a stop as opposed to downshifting to 2nd and pushing the clutch in right before the car stops. It's a myth that the higher your RPMs are the more gas you are using.

EXsoccer1921

iTrader: (14)

^^haha if you're injectors aren't putting fuel into the engine then the engine is off

chris88z24

No..

warrenb213

meh, just shift @ 3k. I get 26 in the city light to light etc, and 31 on the interstate. in portland where the hills are everywhere i've found that with the added throttle that must be given in higher gears, about the same gas consumption occurs as if you just had more readily applied less throttle in a lower gear.

chevy cobalt 08

LMAO I hate high revving sounds like the engine is gonna friggin explode... especially in first... OMG lol but how good is it really for the engine to be revving high like that I mean can something really break at high revving?

chris88z24

No. That's what the redline is for lol. Of course don't go driving down the interstate at redline or some ungodly high RPM, over time it'll wear out your engine pretty fast (common sense here). As far as downshifting is concerned, no. Engine braking actually cools your cylinders, so if you engine brake especially after a long WOT run it will help cool your engine down.

EXsoccer1921

iTrader: (14)

so then if you're injectors aren't puttin gin fuel whats it running off of? air?

chevy cobalt 08

oh wow... I never knew that... see I had to learn manual on my own, so naturally no one told me about any of this stuff.

chris88z24

The engine is connected to the tranny through the clutch, and the tranny is spinning at X RPM's because its directly connected to the axles which are being spun by the wheels. Momentum keeps the car running. If you don't believe me, put the car in any gear as you are driving down the road and turn the key off. Same concept with the engine running, except the computer controls the injectors so when you go to N or accelerate they spray accordingly.

No one told me either. I've been into cars since I was 12 or so ( 18 now), so i've picked up on a LOT of stuff over the years. I may be young but I know my share.

M-Dub

It's called dieseling.... very little fuel is being used it is running off of the compression!

aveoturbo

wow, this is news to me as well and ive been drivin a manual for 3 years now.

chris88z24

Precisely. I couldn't think of the term.

chevy cobalt 08

here's a suggestion.. how about someone create a topic (that should get stickied) and basically put tips and common myths about manuals and such. I'm sure there's some people (like me) that don't know some things. I think it's a good idea especially for those new at manual. and it don't have to be just you everyone can post tips and myths and anything else

chris88z24

I was going to make a "how to drive" video but I havn't had the time.

EXsoccer1921

iTrader: (14)

^^yeah, i understand that concept. but it still requires fuel, but very little. and yes you can turn your engine off in any gear and still go, its called coasting.

think of it this way. if you can run your engine without putting fuel in it then why do we still have combustion engines and not all hybrids? you're engine cannot run on just air. and even if you turned off your engine, as soon as you do the oil stops circulating and youre tearing the **** out of it

chris88z24

No it doesn't. I said when your foot is off the gas. AKA coasting or dieseling. When you accelerate it uses fuel obviously. The oil pump is driven either by the belt or the camshaft. The engine is still spinning even if the injectors are putting 0.00LPH (Liters per hour) into the motor, thus it's still circulating oil as well..

EXsoccer1921

iTrader: (14)

okay well your engine has to have fuel to run. period. even if your foot is off the gas it is still being injected with fuel. but very little, just enough to keep it running.