Gas Mileage

[headhound]

My 2009 automatic just turned 6000 miles and in my commute with stop and go and highway I seem ot be right at 22.5 with everything. I just made my first longer trip and at 65 -70 on the freeways with the AC on I got 26.4. Is this typical of the GT or am I lucky?http://forum.grrrr8.net/images/smilies/th_image003.gif

[WickedMom]

I would say typical with a light foot.

[gearhead455]

I'm only getting around 14 mpg. according to my DIC.:(

and that is just daily commutes with a light foot!!!

[dline]

hmmmm.....good to hear

but why is the other guy getting 14???

[G8+6=fun]

The best I have ever got was 17 and that was at 65 mph with air on. 11 in town with ac on. No hard driving. With 93 octane.. Stock off the floor. 2009 Auto.

[grandmacpubah]

I get about 18.5 with mixed city and hwy...mostly stop and go in seattle lol...but I drive like a mad man every chance I get...so I'm surprised it's not worse. i do have to give a plug for the VMS tune though, my mileage definitely went up after getting the tune.

[timg8]

I'm only getting around 14 mpg. according to my DIC.:(

and that is just daily commutes with a light foot!!!


hmmmm.....good to hear

but why is the other guy getting 14???

Perhaps lots of lights and slow moving traffic?


The best I have ever got was 17 and that was at 65 mph with air on. 11 in town with ac on. No hard driving. With 93 octane.. Stock off the floor. 2009 Auto.

Over how far a distance and what kind of traffic? Is your G8 the sedan (screen name)? If that is all open hwy and yours is the 6, I would wonder what is up.

My G8 GT is on par with grandmacpubah and my wifes daily drive is heavy traffic with lights, at least on the ride home. Yes it is her daily driver.

[atlasshrugged]

17.9 mpg on the clock over 5400 miles mostly daily commute.

[JAM]

24 mpg on 500+ mile trip, but under 18 mpg overall so far in first 6 weeks of ownership.

JAM

[gearhead455]

The sticker on these cars says 15 city and 25 hwy. so I guess 14 is close.:hang::puke::spank::wacko:

[Fatdaddy]

Idling in these cars absolutely kills your gas mileage. Accelerating from stops matters less than the length of the stops. My wife complained about getting poor mileage. Further investigation revealed that she sits in the bank teller line, drive thru cleaners line, junk food line, drive thru pharmacy line, post office line and does this around town with all the traffic lights and rush hour traffic lines. Its hot so she is idling with a/c on.

I don't do that stuff. I hate lines so I park and go in. I don't do errands during rush hour. Net result, she got 14 on her tank, I get 19. I averaged 27 driving down to Charlie's and back.

[dline]

sounds like an hsrk??? would help for daily driving in traffic

[TurboSS]

i just did a little trip the other day....light winds 82* with 87oct. 65mph with cruise on 29mpg down the highway and 28mpg coming back with a/c on!!! then i was able to get 30.1 with a/c off windows 1/2 down with me doing the go pedal. when doing 55mph with cruise on going to work i am seeing an aver. of 32-33mpg, with vararam, poor-mans catback and no tune yet :(

[Superdave]

First trip with mine this past weekend. 220 miles each way. Running pretty hard when I had the chance as I was anxious to get to the beach for a long weekend with my awesome girl. Anyways got 23.0 and average speed was just a tick over 80mph. Had a few 120mph spurts and my girl didn't even know. This car is really smooth at speed!! :D Took it easy on the way back as I wasn't really in a hurry to get home and was rewarded with 25.5mpg. I forgot to look what my average speed was but It had to be around 70. I don't think I got over 75mph at any time and I generally had the cruise set at 70.

[steve b.]

best i ever got is 26 that was going 61 mph

[WARLOCK]

I guess Im right in the middle ofthe hunt. I been avg. around 18.5 for the last two weeks I have had mine and thats 50/50 mix highway and stop and go with a few foot romps. today 62 mile highway trip to work set cruise at 78mph. slowest trip i have made to work but was worth it. 24.0 so.. Im not bitchin. Hope mine DOES improve when I plug in the HPtuner magic.

HEY SUPERDAVE! you going to scrappin the coast this weekend man?

[PaFromFL]

With the four cars I've monitored (the G8 is not one of them), E10 reduced my gas mileage by about 10%. I'm guessing the EPA uses real gasoline for their mileage tests. Lately the mpg loss has varied between 3% and 10% so I'm guessing the fraction of ethanol in E10 is no longer constant.

[netmand]

I get around 21-22 with mixed driving. This is up from 19-20 before tune.

[Chewy]

I run ethanol 93 and get anywhere from 16 to 24.5 mpg per the DIC. I've never checked it out mathematically.

[R.Penguin]

I'm only getting around 14 mpg. according to my DIC.:(

and that is just daily commutes with a light foot!!!
Driving around town, county, always in Manual. I love the way it sounds and the sound when downshifting and using compression braking. But then I have glasspaks. Get about 14.

[grandmacpubah]

gas mileage sucks in seattle because there isn't anywhere flat lol...you're always on the gas pedal going up hills.

[Superdave]

HEY SUPERDAVE! you going to scrappin the coast this weekend man?

No, didn't know bout it. I need to try and make cruisin the coast this year though. :)

[UGotSmkd]

I don't know how some of you are getting 11-15 mpg on a light foot. I never dip below 20 and that is mixed driving (sometimes spirited) with the A/C on half the time . You might want to get someone to take a look at it.

[WARLOCK]

No, didn't know bout it. I need to try and make cruisin the coast this year though. :)

Man u need to try and make it this weekend if possible. Scrappin always has a good mix. There is everything from mercedes amg's, blown 69 camaros, 4x4 F250 trucks on 54inch tires, and yes low rider trucks. its car show, crank it up, vendors, and one year they even had a SOLO coarse set up! Im bringing my Jeep down to compete in the 4x4 ranks.
lots of beer!!!

[SilvaChris1]

27.3 MPG from southern WV to Myrtle Beach, SC. 27.0 on the way back. Cruise was set at 3mph over the posted limit.

By the way, if any of you guys know somebody that wrecked a newer model, Maroon Monte Carlo in front of an Ignition Orange G8 GT on the 13th, tell them that was awesome.... and that they're lucky I'm a decent driver...

[Atlas]

^where in southern wv are you?

[Vertical]

I don't know how some of you are getting 11-15 mpg on a light foot. I never dip below 20 and that is mixed driving (sometimes spirited) with the A/C on half the time . You might want to get someone to take a look at it.

I know that it's been mentioned that an intake and tune increases mpg by 2-4. My bone stock 08 GT gets between 16-17 mpg with the occassional spirited driving and 65/35 hwy/city driving.

I'm hoping that the talk of mpg increasing when the engine breaks in a little is true. Right now I have around 1750 miles on her.

[Habibus]

The best I have ever got was 17 and that was at 65 mph with air on. 11 in town with ac on. No hard driving. With 93 octane.. Stock off the floor. 2009 Auto.

You will get better gas mileage with 87 since that what the stock tune is for. 93 can actually hurt your engine with buildup and all that crap.

[GT-610]

You will get better gas mileage with 87 since that what the stock tune is for. 93 can actually hurt your engine with buildup and all that crap.
ummm,noooo. 93 burns cleaner and the manual says to use premium for high performance.its your choice to spend 40 cents more a gallon for the extra 6 hp.I dont,but hey.

[SilvaChris1]

^where in southern wv are you?

Madison/Danville area. About 35 minutes/miles outside of Charleston.

[chuckwi11]

Those that are getting 20+ mpg I don't know how you do it and keep it fun. I don't think you can get an LSx to balance fun and economy without being boring. My TBSS gets 16-18 as long as I have it on the interstate (let's not talk about doing 75-85 on I-4 to keep up with traffic). Around town, write it off... 12 mpg is the best I have seen. My GXP get a bit better on the road 17-20 but get that M6 on a stoplight chase and it heads dows to around 15. I don't even look at the gas pump anymore... open wallet, push 93, no receipt!:wacko:

[Atlas]

Madison/Danville area. About 35 minutes/miles outside of Charleston.

come to roanoke, va next friday if ya can, theres a huge carshow/cruise that weekend...

[Habibus]

ummm,noooo. 93 burns cleaner and the manual says to use premium for high performance.its your choice to spend 40 cents more a gallon for the extra 6 hp.I dont,but hey.

There is no premium tune in the PCM at all, only maps for 87 octane. Also there is no mention of premium in the manual, only 89 octane for towing with the V-6. It would be like running 93 octane in a Cavalier for performance.



Gasoline Octane

If your vehicle has a V8 engine, use regular unleaded gasoline with a posted octane rating of 87 or higher. If the octane rating is less than 87, you might notice an audible knocking noise when you drive, commonly referred to as spark knock. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. If you are using gasoline rated at 87 octane or higher and you hear heavy knocking, the engine needs service.

If your vehicle has the 3.6L V6 engine (VIN Code 7), use regular unleaded gasoline with a posted octane rating of 87 or higher. For best performance or trailer towing, you could choose to use middle grade 89 octane unleaded gasoline. If the octane rating is less than 87, you might notice an audible knocking noise when you drive, commonly referred to as spark knock.

[headhound]

Last Wednesday I switched to Amzoil 0W-30 Signature Series motor oil and their low viscosity automatic transmission fluid. The car is indicating 24 MPG on my commuting (DC stop and go with AC).

BTW, my car does get its "exercise" as part of its regular driving.

Looking at gas prices and as nice as this car is I am glad I have the G8 instead of another BMW V8.

All we have to do is to get an investment group to buy the Pontiac name and the Holden group. Best of al possible worlds for the future.

[steve b.]

was getting 26 changed oil to amsoil now same speed im getting 27

[GR/G8/GT]

After 3500 miles, I'm averaging about 19.5 around town, and just over 24 cruising the interstate at 80, AC on. BTW, thus far I'm surprised how accurate the DIC is. Mine only has about .1 MPG difference from what I calculate manually.

[blackoutgt]

a whopping 33.4 going down a country road...with cruise control set at 40 mph... then I nearly shot myself b/c it was sooooooooooooo slow. G8 are meant to go fast!

[jonjones88]

Those that are getting 20+ mpg I don't know how you do it and keep it fun. I don't think you can get an LSx to balance fun and economy without being boring. My TBSS gets 16-18 as long as I have it on the interstate (let's not talk about doing 75-85 on I-4 to keep up with traffic). Around town, write it off... 12 mpg is the best I have seen. My GXP get a bit better on the road 17-20 but get that M6 on a stoplight chase and it heads dows to around 15. I don't even look at the gas pump anymore... open wallet, push 93, no receipt!:wacko:

Get out of here, the is a GT forum, hehe :nah:. I have a 07 Sierra Denali and get about 14 on premium. I traded my Silverado SS for the Denali, cuz the Denali has 400hp, but my Silverado SS had more pickup with less hp. I almost went for the TBSS, we had a TB and the interior sucked. Thats the only thing that held me back, but it is a bad ass truck.

[sweetair]

I just averaged 25 mpg highway over 170 miles to NY doing 75 mph or so. I'll take it.

[-Ray-]

I got 27.6 on the way to the race track on Sunday. Then ran a 12.85.

[gnshpr]

just returned from a trip to NE AR hilly curvy starts stops small towns etc got 24.5 with the active fuel management turned off and 87 octane tune car has 2000 miles hope to see improvement but that aint bad

[Greed4Speed]

We knocked down 24 mpg on a recent trip in the GXP. Thats w/under 500 miles on the drivetrain. Its much better than the best of 18.5 we got out of the TBSS and the car is more fun to drive.

On a side note, I got 30 MPG out of my Camaro when it was close to stock. Gotta love the LSx/T-56 combo.

[5letr]

18 -19 mpg in mixed traffic to and from work. I just made an 800 mile trip and got 24.5 overall doing 75ish with three of us and luggage.

['02 ws6]

24 avg on the highway on both trips I've taken in mine. That's usually doing somewhere between 75-80. Was close to 450 miles on the tank. What's sad is I rented a Corolla S last weekend, did the same speed, and only got 328 miles on the tank, which is a 27.3 avg. That's why I don't need an economy car, I'll spend the extra $15 to fill up, and have MUCH better looks and power too boot.

[GrandPrix98GT]

I do almost 90% city driving. My car has averaged 15.07mpg since I got it in September. However, over the last three fill ups, it managed 17.19, 18.19 and 16.44. :headbang: