• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

MPG's

apierce1289

apierce1289

New member
Ok so i have a NA 02 grand prix. As of now im getting 21mpg on the display thing. I have talked to a few local friends that pass through my gas station i work at, they have the same car. They mentioned that they get around 26mpg. My car has about 98,000 miles on it, so my o2 sensor could be going and not reporting the right info. That was my first thought, but i am going to be installing SD headers soon with a 180* t-stat, plus EGR block off plates and an overkill pcm. Should i expect to see my mpg go up or down? Btw i wont be running a CAT Overkillwill is going to disable the whole CAT diagnostic for me and the EGR system :D

Also wondering what do you guys think i should expect for performance out of this setup? I plan on an HV3 insert soon as well :)
 


apierce1289 said:
Ok so i have a NA 02 grand prix. As of now im getting 21mpg on the display thing. I have talked to a few local friends that pass through my gas station i work at, they have the same car. They mentioned that they get around 26mpg. My car has about 98,000 miles on it, so my o2 sensor could be going and not reporting the right info. That was my first thought, but i am going to be installing SD headers soon with a 180* t-stat, plus EGR block off plates and an overkill pcm. Should i expect to see my mpg go up or down? Btw i wont be running a CAT Overkillwill is going to disable the whole CAT diagnostic for me and the EGR system :D
Click to expand...

EGR delete will lower MPGs. And I get about 24ish highway and 20ish in city.
 
01 gtp, 89k miles, solid mix of highway/city driving with some swooping hill travel as well. Always get ~25mpg (calculated, not based on the screen). Highway driving only puts me at 27-28mpg. It's all in your driving style. Stay out of the gas, very gradually increase speed, slowly decelerate, and watch your mpg increase.
 
180* tstat will lose mpg without any performance increase.
Blocking off EGR probably will, too (without any performance increase) if you ever do highway driving.
Headers will gain like 2mpg.
Tune will get back some mpg as well.

At your mileage, your spark plugs are toast. Stick in some new stock iridiums or Autolite XPs. May as well replace your plug wires while you're at it. And take out the stock airbox and slap a huge cone filter on. That'll increase mpg as well.
 
+2 on the Open cone intake and headers. I just did both of these on my gtp. It is time for a plug/wire change.
 


I already have an open cone on the throttle body and I'm waiting to do spark plugs when I do the headers :) Are the upgraded wires for our cars on zzp worth it with my mods? What model spark plugs should I get?
 
Our 98 GrandPrix GT 2 door gets about 30ish on the hwy, 22 in the city if driven easy. Its got about 259,000Kms on the clock.. (160,313 Mi)

Jay
 
I got auto lite 606's & auto lite plug wires. Are those fine? Also im putting off my header install untill i do my top swap so will those spark plugs be fine or should i get colder ones for the install? Also what is exact brand and model you recommend for SC'ed?
 
21mpg average sounds perfectly reasonable. One thing you need to realize is that most everyone either lies or embellishes about their horsepower, handling, or even MPG's. You either have to do a lot of highway driving or pay VERY close attention to how you drive to average 26mpg in a GP.
 


You must log in or register to reply here.
Back
Top