3.8L V6 Automatic, any tips?

[Varn]

RE corridor effect.
Driving slower than traffic will save you mileage as every vehicle that passes first pressurizes the air behind then creates a draft as they pass.

I would say that 2000 rpm may be too high for max economy. My 3.8 Ford v6 is better at 1500-1700. You need an instantaneous fuel gauge to tell. You won't believe how little throttle opening and speed will drink your fuel.

[nemo]

Originally Posted by Varn

I would say that 2000 rpm may be too high for max economy. My 3.8 Ford v6 is better at 1500-1700.

With the method I'm using it is only a 2k in first and second subsequent shift are at lower rpms. Sure is worth a try though.

Originally Posted by Varn

You need an instantaneous fuel gauge to tell.

No argument there. If it could only log ever time you accelerate from a stop and tell you which one you did better on and if the conditions were the same. Then you would more easily be able to improve.

Originally Posted by Varn

You won't believe how little throttle opening and speed will drink your fuel.

Oh but I do! The ultra gauge keeps reminding me.

[ktaylor]

Thanks for your replies,

I've come to the conclusion that a UG is the only way to go.

Does anyone know more info about our transmissions? I've heard they have 3 intermediate settings totaling 12 gears. Anyone know how this works/how to use it to our advantage?

[comptiger5000]

The "intermediate settings" likely refer to something such as 1st gear, 2nd gear, 2-lock, 3, 3-lock, 4, 4-lock. Basically just different combinations of gears and lockup.

[ktaylor]

Yeah probably.

If I wait until the tank is closer to empty my FE will go up right? I realized I've been filling with 20L or so still in the tank (1/3 full) because my fuel gauge craps out at around 30L and either always says the tank is full or says it's empty.

Thinking about it, the sg of gas ranges from 0.71-0.77 according to wiki. That means it's 710-770kg per 1000L, so if I let my car run down to about 5L my car would weigh 15L = 10.65-11.65 kg less. A linear decrease from 20L to 5L gives an average reduction of half that meaning 5.33-5.83 kg over that range. They say 100lbs reduction is 1-2% so I'm looking at 0.118-0.257% increase in FE, for my car thats about 0.033-0.071mpg.

Oh well, that could've turned out better... Atleast I know I can get that 0.1 rounding in there sometimes, and I won't have to go to the gas station as often lol.

[ktaylor]

Originally Posted by nemo

If I do it correctly I can reach 4th with it locked up at 38 to 40 mph (61 to 64 kph). After some checking my transmission has overdrive gear for 4th at .7 and a final drive ratio of 3.05.

What do you mean by "do it correctly"? My car has to go up to 47mi to downshift and I have the same 0.7 4th gear and 3.05 final drive.

Is there a chance GM changed the shift points on our ETM's? Minor change in the code I imagine and presto, lower shifts. If I only knew how to do it to mine...


What rpm's are you holding when it drops to 4th? It must be close to 1100 or so.

[ShadeTreeMech]

Originally Posted by ktaylor

Yeah probably.

If I wait until the tank is closer to empty my FE will go up right? I realized I've been filling with 20L or so still in the tank (1/3 full) because my fuel gauge craps out at around 30L and either always says the tank is full or says it's empty.

Running an emptier tank will save a bit on weight, but it will allow the fuel pump to get warmer than with a fuller tank, which can shorten its life. There's also the argument that giving the gas too much space to evaporate into means more fuel is lost to evaporation. Granted, the charcoal canister is supposed to absorb all the fumes and release them during driving, but I suspect you'll get no extra economy from the fumes released by the charcoal canister.

And the "except at the pumps" comment referred to a bit less fuel needed to refuel.

[rmay635703]

Originally Posted by ktaylor

What do you mean by "do it correctly"? My car has to go up to 47mi to downshift and I have the same 0.7 4th gear and 3.05 final drive.

What rpm's are you holding when it drops to 4th? It must be close to 1100 or so.

??? My buick lesabre had 2.8ish gear ratio I would hope the regal was the same, meaning he could well shift earlier with a lower final drive like that.

[trooper Tdiesel]

are base model impala has no rpm gage
rater impractical to do a engine swap but are 03 impala has the 3.4L

mpg for a 3.4L
Compare Old and New MPG Estimates

mpg fpr the 3.8L with no super charger, if it was S\C drop the mpg one more for each city/highway
Compare Old and New MPG Estimates


also any one know or have a 3.4 or 3.8 with a manual trans?
ive yet to find one, though ive wounderd if a manual from a Oldsmobile Achieva would work, likely not being a I-4 in it but its an idea.
i think its about the same size as a Malibu
Compare Old and New MPG Estimates .

[ktaylor]

Originally Posted by rmay635703

??? My buick lesabre had 2.8ish gear ratio I would hope the regal was the same, meaning he could well shift earlier with a lower final drive like that.

According to wiki, the Lesabre has a 2.86 final drive but mine has a 3.05. According to fueleconomy.gov, our cars get the same mileage. I wonder how much of a difference it would make to swap the 3.05 for the 2.86. Has anyone done a final drive swap before? Notice any improvements?

Originally Posted by trooper Tdiesel

also any one know or have a 3.4 or 3.8 with a manual trans?

Apparently there's never been one made for a front wheel drive 3.8L. I read on a forum that its possible to build one but its a PITA and really expensive. If you want a standard so bad, sell it an buy one. I'm planning on doing that very soon...