GM should've put baffles in the gas tanks...

**SubwayGuy** · 07-24-2015

I'm 90% city driving though.

**EHB** · 07-24-2015

Originally Posted by J57ltr

So is the fuel mileage thing a 5 button DIC I hear about? I always just have to figure it by resetting my Trip odo when I fill up, then dividing from there, well since I got an app that keeps track I use that now.

Jeff

**EHB** · 07-24-2015

Originally Posted by HighOctaneRacing

City MPGs with hilly terrain swallows big time on a stock tune. Get a tune. It'll pay for itself

Sent from my LG G3

i drive mostly city and hilly terrain and i lost about 1.5 mpg when i installed an overkill pcm. i was getting just over 16 now i'm under 15.

**J57ltr** · 07-25-2015

Originally Posted by EHB

05' is different, no? Mine just has 3 buttons below a smaller display.

Jeff

**SubwayGuy** · 07-25-2015

The display you see is for 6th generation GP's. 7th generations have a littler display that can either come with 3 or 5 buttons.

**blueguy** · 07-26-2015

I get more than 250~ miles to a tank on E85 LOLOLOL.

And anyone that uses the DIC as an accurate tool to calculate gas mileage needs to stop. It's off. Always has been. GM got better over the years but even my Cobalt was wacky, and it was brand new.

Use some math, lazies. Miles driven/gallons. I mean, it is rocket science after all.

I average about 240-260 in the GXP, and it's always getting about 15~ gallons on fill up after it gets around an eighth of a tank...not to mention that is with 3.69's. My '98 won't take more than 13~ gallons, ever. I think the most I've put in that thing is 12.8.

**Scottydoggs** · 07-26-2015

i still get crappy local mpg, 14's as per the dic. but thats a lot of stop and go.

**99GT2dr** · 07-26-2015

I also get better than 250 miles/tank using E85, that's horrible for gas, lol. From what I understand, the dic uses the IFR to calculate mpg, and obviously gear ratio and what not that calculates speed. So if your IFR is off, or maybe larger wheels/tires that throws the speedo off a little, it would throw off the dic readings. On my G8, it's usually spot on, maybe .1-.2 off on the mpg, surprised the hell out of me. The regal is pretty close too, but I forget how close (never enough to make me go "wtf?"), I usually just punch the numbers in my fuelly and go by that.

**16MustangVet** · 07-29-2015

Read 1st page stopped skipped back to here........

Tell you same thing I tell my wife...........

STOP DRIVING IT UNDER 1/8 TANK! I seriously wish cars would just shut down on their own with any small loss of fuel pressure that would keep people from destroying pumps because they try max out the tank capacity...... No you don't need to get every last drop lol!

Hell I don't let mine ever go below 1/4 not like you can just stop buying gas so why avoid it?

**SubwayGuy** · 07-29-2015

Originally Posted by 98bleedingaholevet

Read 1st page stopped skipped back to here........

Tell you same thing I tell my wife...........

STOP DRIVING IT UNDER 1/8 TANK! I seriously wish cars would just shut down on their own with any small loss of fuel pressure that would keep people from destroying pumps because they try max out the tank capacity...... No you don't need to get every last drop lol!

Hell I don't let mine ever go below 1/4 not like you can just stop buying gas so why avoid it?

Because I'm sure GM wasn't like "Let's make it so when you have 1/8 of a tank of gas, your fuel pump burns out." I will take my chances with it. All I was saying for this thread is that I've never been in a car other than mine where I can watch the gas needle go down when hitting the brakes hard.

**bandook** · 07-29-2015

It really shouldn't fluctuate level that much. But my car does seem to register quicker than most cars I've had. I would assume there is a delay of some sort programmed into the pcm for the sender before it sends the level to your cluster. There has to be some delay otherwise every time you turned, hit a bump, whatever the needle would bounce around. It would register like a tractors gas cap with the float and gauge attached together.

I seem to remember something in the tiny tuner tables regarding this.

**J57ltr** · 07-29-2015

Well they are pretty much baffled and I have only had 2 pump failures in my entire driving career one was a S-10 that a friend complained for more than 3 years that his truck would lurch and had no power but every time I asked him if he changed the fuel filter he would say no and 3 months later he would ask the same question. When I used a timing loght to look at the spray pattern every time you revved it up it went from a cone to a dribble. I ended up with that truck and the filter was so clogged that when I blew into it, it was like filling a balloon and I was afraid that it was going to spit gas in my face. It actually had vapor form when I released it. That pump failed 2 weeks later. The other was on an SC and I was able to get it to the shop after pounding on the gas tank.

How many pumps actually fail due to low fuel? I guarantee that the vast majority of pump failures are due to the brushes being worn out.

Jeff

**J57ltr** · 07-29-2015

Originally Posted by bandook

It really shouldn't fluctuate level that much. But my car does seem to register quicker than most cars I've had. I would assume there is a delay of some sort programmed into the pcm for the sender before it sends the level to your cluster. There has to be some delay otherwise every time you turned, hit a bump, whatever the needle would bounce around. It would register like a tractors gas cap with the float and gauge attached together.

I seem to remember something in the tiny tuner tables regarding this.

Bandook,

What about the tach? The one in the GP seems sooo slow compared to the tach in my Park Ave. When it has a gear change the tach drops almost instantly, but in the GP even after the shift it just slowly drops.

Jeff

**bandook** · 07-29-2015

I was just discussing this in another thread a few days ago. I'm actually quite impressed with how fast the 3800 revs. Its not Ferrari fast, but it doesn't hang near as bad as other cars I've owned. I don't think there is much you can do about it though. Lighter rotating assembly maybe? Or try some Moli Lube. I just put a can in my car, its moly disulphide. Read some reviews that people claimed quicker revs and throttle response. Haven't noticed it yet though. But as with any additive, there is plenty of opinions on both sides. I was researching it for another project when I came across the additive. Can't see it being anything but good, Moly D is an amazing product, second only to Teflon in reducing friction I believe.

**chrsmi1** · 07-29-2015

Originally Posted by 01Grand PrixGT

Because I'm sure GM wasn't like "Let's make it so when you have 1/8 of a tank of gas, your fuel pump burns out." I will take my chances with it. All I was saying for this thread is that I've never been in a car other than mine where I can watch the gas needle go down when hitting the brakes hard.

We have the opppsite problem. I can watch my gas needle go down when I hit on the gas......

**J57ltr** · 07-29-2015

I am more referring to the gauge not keeping up with the engine. My 97 tach is quick to react but the 05' GP is lazy. Kinda like you were talking about the gas gauge.

Jeff

**bandook** · 07-29-2015

^^^ lol. Yup, same problem. And because of my crappy hack job on my canister I can't let mine go below 1\4 tank or it dies when I come to a quick stop or turn while accelerating.

**stealthee** · 07-29-2015

Originally Posted by J57ltr

I am more referring to the gauge not keeping up with the engine. My 97 tach is quick to react but the 05' GP is lazy. Kinda like you were talking about the gas gauge.

Jeff

That difference is most likely related to DBW.

**J57ltr** · 07-29-2015

So do you think there could be something to speed up the tach, like you were talking about the fuel gauge? I'm fine with the fuel gauge on my car, but the tach is just too lazy.

Jeff