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What's Your Fuel Economy for Your Vert(s)?


Rick

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So...basically when I drive I should lock the shifter in the "3" spot instead of "D"? Im averaging also still 14-16mpg.

 

depends on what kind of speeds you're traveling at.

 

In 3rd the rpms are going to be slightly higher than in D. I just checked mine and I'm getting about 17.6mpgs.

 

and this depends as well... if the TCC is locked in 3rd, it will PROBABLY be at lower RPMs than if the TCC is unlocked in 4th. there are exceptions, but it's also not critical, since RPMs alone do not determine fuel economy. the issue between 3rd/locked and 4th/unlocked is that with the TCC locked, there is basically no loss of power through the torque converter, but unlocked, there is a lot of slippage in the converter, meaning it's just making heat instead of moving the car forward.

 

 

 

taking a look at the 94-95 LQ1 stuff now. BSBH(latest cal i know of):

 

TCC will lock in 3rd gear as low as 32MPH.

TCC will lock in 4th gear as low as 48MPH.

2-3 upshift will happen as low as 22MPH.

3-4 upshift will happen as low as 48MPH (interesting "coincidence").

 

so, in this application, manually holding the shifter in 3rd will most likely NOT improve fuel economy....

 

however, in the factory 3100 calibrations, much different story. those will almost always bump into 4th gear before ever attempting to lock the converter in 3rd gear, unless you manually select it. been a while since i looked at the 3.1 calibrations, so i'm not going to comment on those.

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in the factory 3100 calibrations, much different story. those will almost always bump into 4th gear before ever attempting to lock the converter in 3rd gear, unless you manually select it.

 

Thank you for this knowledge, I've often thought the 94 sedan was crazy for shifting into 4th right before locking the converter when 3rd gear lock is what I wanted to occur...

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since i have it open....

 

latest 93-95 3100 W-body calibration:

 

2-3 can happen as low as 20MPH

3-4 can happen as low as 32MPH

TCC in 3rd can happen as low as 44MPH (thanks a lot GM)

TCC in 4th can happen as low as 45MPH

 

so you can only hit TCC lock in rd if the shifter is in 3rd and above 44MPH.... in which case, you may as well be in 4th and hit 45MPH..... :facepalm:

 

in my own calibration..... i have those TCC lock points significantly lowered.... 35MPH(3rd) and 36MPH(4th). shift points are also different for 3-4 at min throttle(34). SO much more likeable.

 

for whatever reason..... if you shift from 3rd-4th with the TCC locked, it's REALLY firm.... i don't remember liking just how fast it was, otherwise, i had TCC locking in 3rd around 28MPH, felt great.... until the shift. and i don't think there was enough room left on the T-side PROM to impliment a modified 3-4 upshift routine to mod the TCC PWM circuit during the shift to slow it down a bit. i may look into it again.

 

odd thing: the old-school 4T60 and 4T60E without PWM? they didn't have any issues with a TCC locked 3-4 upshift.

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I clipped the PWM wire quite some time ago, made for an all around more pleasant experience.

When I get the TGP driving again I shall certainly PM you about 3100 tuning.

In the meantime I will quit hijacking this thread. :lol:

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most of my driving is just sunset cruises.

 

93 dohc vert

 

when cruising i run up the speed just far enough to get tcc lockup in high gear at about 1650 rpm......i havent done an actual calculation but expect close to 30mpg at this cruise speed of about 46mph if i remember right

 

what i do know.....she sips gas at this speed and rpm

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Just took my '92 CS Convert (3.1L) on a long trip last month and averaged 24 mpg highway. In the city I get 16-17 mpg, driving quick off the stop lights.

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  • 2 weeks later...
  • 3 weeks later...

Just came back from vacation to the North Carolina mountains and avg 23 mpg on the trip. Driving up and down the mountain roads maybe 15 mpg. I burn regular with Lucas top cylinder lubricant on almost every tank.

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  • 7 months later...

both my 95's LQ1's get 16-17 in town and 24 mpg highway. Pretty consistant. I swapped out the LQ1 with L26 leaving the 3:43 trans and my gas mileage in town is about 19 mpg in town and 26-28 Highway.

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  • 5 months later...

Welcome to W-Body, and you did do it right. :thumbsup:

 

No chip or program is going to increase your mileage...keeping the car in good tune makes a huge difference. Biggest improvement with mine was replacing an old O2 sensor. I drive mine just under 300 miles a week, around 60/40 highway/city driving, and I pretty consistently average around 20.5-21.5 week after week, and around 27 on highway trips.

 

It's going to sound as if I'm being a jerk, but absolutely the biggest factor is your right foot.

Does anyone know of a computer chip or program that will increase MPG on a 94 vert 3.4? Thank you. My first post, I hope I did it right.
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No chip or program is going to increase your mileage....

 

ehh...... i wouldn't say that. i got a solid 10% bump on the highway after playing with the wife's car enough. cruising at an AFR of 16.2:1 would probably get hit hard by the emissions police, but it helps MPGs.

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Robert...forgot you're the maestro of the mysteries of GM software...but for most people not personally acquainted with you, they're not likely to find a chip or tune for a 20-year-old W...

 

But if he asked you nicely...:lol:

ehh...... i wouldn't say that. i got a solid 10% bump on the highway after playing with the wife's car enough. cruising at an AFR of 16.2:1 would probably get hit hard by the emissions police, but it helps MPGs.
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How are you managing that? I would be happy with that. I am getting about 16/17 average per tank. I guess I need to do some major tuning. What does everyone think I should start with? I am a woman with limited mechanical ability, so if it is complicated, just tell me to take it to a shop. Thanks everyone!

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I averaged 19MPG my last tank in the Cutty. That tank lasted me a few months so I can't complain.

 

Dollfinzz1, start with something simple. Check your air filter.

 

Spark plugs, spark plug wires, fuel filter...etc

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