Skip Shifting... Fuel Economy/Engine Longevity

[ModsAway]

I know our cars definately have the low end power to handle a skip shift from 1-3 or even 1-4 but it begs the question ... why?

Is this approach to shifting going to save us any gas? Reduce stress on the engine? Or what? What are the upsides and downsides to skip shifting?

The reason I even bring this up is my brothers Trans AM WS6 has a skip shift built into it that FORCES you into 4th from 1st if you accelerate slowly. I hate the sound it makes when you press on the gas again and the RPM's are slightly lower than 1k. GM claims fuel economy as the reasoning, which is stupid of course on a 5.7 V8 but :shrug: Is this truly the reason?

 

[PhillyCobra]

"Skip shift" is 100% to pass CAFE fuel mileage regs on GM cars. First thing I ever did my Vette was disable the thing. It's horrible!!

Might save a little fuel upshifting to a higher gear sooner, but I think it's not worth the stress on the engine (higher load at lower RPM's in higher gear) when you're accelerating. I don't thnik you'll ever wear out your drivetrain by shifting through the gears in the correct order. You will get better fuel mileage if you short shift (at relatively low rpm's) however.

 

[cobra101]

I started a thread on this awhile ago (but without search I can not find it now).

When just cruising around, I skip all the time. I believe there is no drawback (harmful affects). I do it to save some shifting, but I imagine it may save a little gas but not too much. It may save on the clutch a little as I engage and disengage it a little less when going 1st to 3rd to 5th.

When I want have some fun and get on it, I shift all gears of course.

 

[MidLifeC]

I paid for 6 gears and use every one of them.

 

[Rio]

i skip shift all the time, but not to save on gas or the clutch or anything.......mainly because the ratios are close enough where i have to shift out of consecutive gears relatively quickly......

for every day driving i usually go 1, 2, 4, 6....

just less shofting, a little more efficient in my mind for driving.....dont have to row through all 6.....just my 2 cents...

 

[ModsAway]

So only one person so far thinks it may increase the load on the engine (this thread made it to page 3 already, wow the Terminators sure bring the crowds)

I personally started doing it to keep my RPM's down and my exhaust a little quieter. In these cars I find first and second gear really don't last very long when either giving it all you got or trying to shift before the 2k mark (The stingers loudest RPM).

 

[dgussin1]

Originally posted by Raging Rio

for every day driving i usually go 1, 2, 4, 6....

Me too...what the hell is fuel economy, I get 11MPG:bored:

I have a heavy foot:-D

3rd and 5th are for pure acceleration only. I take 1st to 15-20, 2nd to 35, and coast into 4th up to 45.

 

[geepaw]

I do the same and rio...a habit I have been doing since I first started driving.
This is the easiest car to do it in with close ratios and all the TQ. I think it may help,
I just personally think (not a fact) it will
reduce clutch & tranny wear since you are enaging clutch and drivetrain somewhat less. MHO...

 

[Matt M PA]

My GTS has the same skip-shift BS feature too. C'mon...a V-10 and we're worried about fuel economy? I found it doesn't get in the way much if I hold 1st just a bit longer.

Back to the Cobra. I seem to remember reading on these forums that the best fuel economy came by shifting around 3000 RPM.

I don't think it does the car any good by shifting when the light says and having the engine lug.

 

[SnakeBit]

Originally posted by dgussin1
Me too...what the hell is fuel economy, I get 11MPG:bored:

I have a heavy foot:-D

3rd and 5th are for pure acceleration only. I take 1st to 15-20, 2nd to 35, and coast into 4th up to 45.

I guess I'm not the only one. :beer:

 

[adonis]

Originally posted by SnakeBit
I guess I'm not the only one. :beer:

I get around 180 miles between full tank and the 'low fuel' light. I don't think we're the only ones. For best mileage just look at the gas pedal but don't touch it.
I'm not sure how much the skip shift would help. If I'm trying to drive nice (very rare), I shift around 1500 or 2k RPM, just barely open the throttle, and stay OUT of the boost. For those with boost/vacuum gauges, is there a driving style where you can keep the boost and vacuum at zero? This should be the lowest drag on the engine and the best economy (could be wrong here). High vacuum means it wastes power having to suck harder on the intake stroke. High boost means you are making/wasting more power and you waste more power spinning the supercharger.

 

[dgussin1]

Originally posted by adonis
I get around 180 miles between full tank and the 'low fuel' light. I don't think we're the only ones. For best mileage just look at the gas pedal but don't touch it.
I'm not sure how much the skip shift would help. If I'm trying to drive nice (very rare), I shift around 1500 or 2k RPM, just barely open the throttle, and stay OUT of the boost. For those with boost/vacuum gauges, is there a driving style where you can keep the boost and vacuum at zero? This should be the lowest drag on the engine and the best economy (could be wrong here). High vacuum means it wastes power having to suck harder on the intake stroke. High boost means you are making/wasting more power and you waste more power spinning the supercharger.

I have yet to see more than 170mi before I have to refuel, usually around 140-150 for 13-14 gallons

 

[SnakeBit]

Originally posted by adonis
I get around 180 miles between full tank and the 'low fuel' light. I don't think we're the only ones. For best mileage just look at the gas pedal but don't touch it.
I'm not sure how much the skip shift would help. If I'm trying to drive nice (very rare), I shift around 1500 or 2k RPM, just barely open the throttle, and stay OUT of the boost. For those with boost/vacuum gauges, is there a driving style where you can keep the boost and vacuum at zero? This should be the lowest drag on the engine and the best economy (could be wrong here). High vacuum means it wastes power having to suck harder on the intake stroke. High boost means you are making/wasting more power and you waste more power spinning the supercharger.

Most of my driving to/from work is city driving. Slow speeds and lots of stops. There is some interstate (~3 mies), but that is usually at minimum 0 to 60 times and ends in second with a shift to 6. I realize this isn't the best style for economy, but who the eff cares.

A few times a month, I have to drive 50 miles each way, mostly expressway and do so at 70 - 85 mph mostly in 6th, but occasional sprints to 100 in 3rd. This driving gives me significantly better gas milage than my standard routine. It's difficult to measure because it isn't long enough to burn 2 or 3 tanks, but based on miles driven on first 1/4 and then 1/2 tank, it is maybe 30% better.

I'll bet that an extended trip at 80 mph would yield better than 20 mpg. It would even allow occassional outbursts of the childish kind, (A past service manager once told me he could have a Mustang because "It brung out the youngen in me."). Maybe someone with several extended trips can chime in.

 

[caveman6666]

Originally posted by Raging Rio
ifor every day driving i usually go 1, 2, 4, 6....

Same here. Just wind out 2 and 4 a bit more.

 

[IronTerp]

Yea, skipping gears in these beasts to help with gas mileage is kind of an oxymoron..... Convenience? That's another story. When juicing it through 1st and 2nd, I often go straight to fifth if my mph is 45 or so. As long as the engine is not put into a "lug" situation, skipping gears should not have negative affect on the drivetrain. Now, the juicing part....that's another thread!