Compg

Well just returned home from a 4200 mile round trip/ maiden voyage on the GXP and here is what I found about the MPG:
-First off my DIC calculations vs. my pump calculations on the mileage of the car was always within .5 of each other. With my pump calculations being lower.
-Under 2K miles on the car the best I could get at any speed was around 19MPG.
-After 2K on the odometer MPG really picked up alot on the HWY, I can't really say about city driving or with alot of traffic but the HWY improved alot.
-On the last leg of the trip returning home I was on a 800 mile stretch and varied my driving speeds and habits and would fill up about every 200 miles for test purposes. Because once the gas guage hits below 1/2 MPG suffers alot for some reason.
-75 MPH--average of 22.3-fairly flat road not alot of traffic
-70 MPH--average of 24.6-same as before
-65 MPH--average of 26.8-same as before
-60 MPH--average of ***29.4 MPG*** OMG great but it drops really quick if you hit the gas at all.
I don't know if anyone else has found the same results as me but I figured I would share my gas tale with you all. The only thing done to the car at the time of test was Jimmy C 3" DP and resonator removed. I got home to find my K&N Drop in filter and I wish I would of had that on the trip. Maybe in a year or so I'll try again.
Tate

Area47

hmm, seems odd
i was getting 28 with the cruise set at 76 from st louis back to kc.

but i did notice if i roll along at 68 mph, i can average 25 mpg on short city to city trips.

like 30 mile runs

jabronie78

iTrader: (1)

It also depends on what kind of gas you are using. I noticed if I use regular 87 octane I get better gas mileage than if I use premium 93 octane. I've tried experimenting because I drive 30 miles oneway to work a day. I get the best gas mileage going 60 - 65 mph on regular gas.

pgbSS

I found about the same thing. After filling up and calculating mpg on the interstate with cruise going 75 I got 20mpg. On a 2 lane road going 65 I got 25mpg. All city driving I'm getting 17-18mpg. I noticed when driving 75 it very rarely got into 4cyl mode, but at 65 it was in 4cyl mode alot. I didn't buy my Impala for the mpg, but was hoping I would get closer to the highway rated mpg. I guess if I want that I need to drive slower 3 things I was looking for in a car was room for the family, good performance, and good mileage... I guess getting 2 out of 3 ain't bad. Still a lot better mpg than my Z71 I traded in.

HardBlu

I have less than 2,500 mikes on the clock and drove nearly 700 miles last week and I avg around 25 mpg. Most of the miles were were hills with a few long stretchy hills. My avg speed varied from 70 to 80, no cruise due to the hills, but the a/c was cranking in the cab trying to beat the sun dial of 100^ degrees.

I watched the rpms and tried REAL HARD to stay around 2k during the straight a ways to conserve the reg unleaded. Its so easy to let the foot engage to pass when you're close to home. I lost a lot of gas mileage on the last stretch home, around 40 miles. Once you start engaging beyond the 2k rpm, she drinks like a thursty race horse.

The Monte rode real nice though and I can't complain even If I didn't get my MPG est...

98z28chevy

i just got a 06 monte ss my 98z28 seems to get better gas mileage figure the monte should be better with D.O.D doesnt seem to help much i be taking it real easy on the gas with the ss hopefully get more miles on it should hopefully get better go the car with 80 miles on it up to about 240 now.

Mike's 01WS6

iTrader: (4)

Your z is lighter, more aerodynamic, and has a stiffer tire that has less rolling resistance, and if it is a stick has a better gear ration in 6th.

LittleMT

iTrader: (1)

I don't get good gas milage at all in my Monte... but I tend to have a heavy foot...

BADDLS1SS

iTrader: (22)

My results are similar... reporting from St.Paul MN right now...

Made a 300 mile trip from Milwaukee to St.Paul yesterday after noon, the DIC was reporting 24.9 with the cruise at 70 and cycling the air on and off, not leaving it on 100% of the time. Im about half way between the half tank mark and 1/4 tank mark with about 340 miles on the trip odometer. That is the most ive got to one tank so far, previously being 330 miles to just about empty, putting 15 gallons in.

4100 miles

Mods are just the tuning, cone filter, Mobil 1 syn 5W30, 160 thermo, and the Hogan Offroad Down pipe.

I will record the pump mileage calc when i fill up before i leave. However i want to get back into WI before filling up on BP 93 octane because MN uses 30% ethanol in the gas. Where most of WI uses regular, non ethanol gas. The tank i used on the way up contained 10% ethanol and was BP 93 which is all that avail in the milw area.

-Tom

Mike's 01WS6

iTrader: (4)

160 stats not helping your mileage.

BADDLS1SS

iTrader: (22)

Not hurting it either... It runs about 185 90% of the time.

I fogot about this thread, i actually came back with 26.2 for a pump calculation vs the 24.9 DIC reading.

On the way home, with non reformulated gas from northern WI, BP 92 octane it managed anywhere from 27.9 to 28.3 on the DIC and turned out to be 27.8 on the pump calculation as well.

Again cruise set at 70, a/c on and off.

BuffaloSS

iTrader: (3)

Oh, boy! I forgot about the ethanol blend come winter time. I'm NOT looking forward to THAT!

Chrsmi1

I go on 245 mile trips from Charleston, SC to right above Charlotte, NC about every weekend. The best gas mileage i get is about 23 average. I average about 71 mph. (the speed limit varies from 70 to 65 all the way down to 55 through charlotte.) I got 10,000 miles on my car and i bought it with 17 miles on it in may of this year. When i drive around town here during the week though i only average about 16-18 mpg. Heavy foot though...

HardBlu

Just finished a 445 r/t drive and I averaged about 23 mpg. As my first post indicated a higher mpg, I lost a few miles per gallon and gas cost less this time. I guess it's how you work the foot...