Last post on Jul 23, 2012 at 9:43 AM
You are in the Pontiac G6
What is this discussion about?
Pontiac G6, Fuel Efficiency (MPG), Coupe, Convertible, Sedan
#44 of 52 Re: 2007 pontiac g6 bad gas mileage [gonogo]
May 25, 2010 (10:05 am)
Your 09 is also compatible with E85 Flex-Fuel, correct? This was not available for the 2008 model year.
The 2008 owners manual states:
"If your vehicle has the 2.4L L4 engine (VIN Code B),
use premium unleaded gasoline with a posted octane
rating of 91 or higher. You can also use regular
unleaded gasoline rated at 87 octane or higher, but
your vehicle’s acceleration could be slightly reduced,
and you might notice a slight audible knocking
noise, commonly referred to as spark knock. If the
octane is less than 87, you might notice a heavy
knocking noise when you drive. If this occurs, use a
gasoline rated at 87 octane or higher as soon as
possible. Otherwise, you could damage the engine. If
you are using gasoline rated at 87 octane or higher and
you hear heavy knocking, the engine needs service".
A 4 cylinder engine would not benefit from reduced acceleration. I also don't want my ride sounding like some beater. Premium unleaded in my area is 93 octane. I will not use a fuel posted 6 octane points lower than recommended. Back in the day, you could get around spark knock by adjusting the timing and fuel mixture. Since cars these days are computer controlled and no user adjustments are available, I'll go with what is stated in my owners manual.
#45 of 52 Re: 2007 pontiac g6 bad gas mileage [maddog0324]
May 26, 2010 (8:32 am)
My engine is code B, 87 octane. Only 09 that will run E85 is the 3.5 VIN code K.
It also states the 3.6 VIN code 7 will run better on 89 octane for towing. Everything else in the 09 line up is 87 octane.
Something must have changed from 08 to09.
#46 of 52 Re: 2007 pontiac g6 bad gas mileage [gonogo]
May 27, 2010 (3:24 am)
They may have lowered the compression ratio for 09. I have not been able to find mechanical specifications for models after 2007 in the online Chilton's I have access to.
#47 of 52 Re: 2007 pontiac g6 bad gas mileage [maddog0324]
May 27, 2010 (8:09 am)
Do you suppose nothing changed and they just dropped the 91 octane rating for sales purposes. It says the engine will run on 87, you suppose if I used 91 in mine I would have increased power?
#48 of 52 Re: 2007 pontiac g6 bad gas mileage [gonogo]
May 27, 2010 (11:24 am)
I think they changed something with the compression ratio for the 09's. They specified 91 octane minimum for the 08's because they knew that the engines would knock loud enough. An engine that normally runs on 87 octane won't knock loud enough that you can hear it. If you run 91 octane in yours, you may see a slight increase in performance and fuel economy. I don't know what gas goes for in your area, but in mine they charge $0.30/gal more for premium vs. regular unleaded. It's up to you if the extra expense would be worth it.
#49 of 52 Re: 2007 pontiac g6 bad gas mileage [pennie3373]
Sep 16, 2010 (4:16 pm)
i have a 2006 G6 i drive 4.7 miles to work and i get 287-310 miles out of a tank of gas and highway i get 497 i just drove from canada to va beach over 800 miles and i filled up once on that trip and had over a 1/4 tank when i got there i did a whole years reaserch on this car 06-09 and the 06 had the best gas mileage to offer and there is not much differant body wise other than the sun roof on the 06 and the radios in all of them i love my car and i dont think i will ever traide it in i bought it with 43000 miles
#50 of 52 pontiac g6
Feb 22, 2011 (8:05 am)
I'm looking a buying a pontiac g6 used with 115,000 miles on it can anyone tell me if this is a good car to get with this kind of miles on it i want something thats gonna last me a few years atleast
#51 of 52 Re: 2007 pontiac g6 bad gas mileage [gonogo]
May 10, 2011 (2:57 pm)
Just got back from a road trip in S. GA / N. FL, 650 miles all freeway. Day temps in the mid 90's, so the A/C was on full-time. I averaged 29.2 mpg 72 mph.
#52 of 52 Re: 2007 pontiac g6 bad gas mileage [maddog0324]
Jul 23, 2012 (9:43 am)
2008 G6 2.4L with 64,000 mi on the 5/10/2011 road trip. I just returned from a 725 mi round-trip N. GA / N. MS on 07/29/2012. Car averaged 29.4 mpg 70 mph with A/C on full-time & 1 adult passenger.