# My Gas Mileage Improved



## C5ORGTO (Dec 30, 2004)

All winter long my average gas mileage has been 12mpg. It would vary between 11.9 to 12.2. Since my last 2 fillups of Shell 93 I jumped to 14mpg. I haven't changed my driving at all. I live 5 miles from work and drive fast all the time. Could the gas stations have changed to a summer blend, or am I just crazy. I've got about 8,500 miles on it and its an 04.


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## HotRodGuy (Jan 9, 2006)

I don't understand how you guys get such ****ty gas mileage, I don't baby my car and avg 18-20

lowest was 16.3 and that was after a few passes at the track

highest was 24.8


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## noz34me (Dec 15, 2005)

C5ORGTO said:


> All winter long my average gas mileage has been 12mpg. It would vary between 11.9 to 12.2. Since my last 2 fillups of Shell 93 I jumped to 14mpg. I haven't changed my driving at all. I live 5 miles from work and drive fast all the time. Could the gas stations have changed to a summer blend, or am I just crazy. I've got about 8,500 miles on it and its an 04.


The hotter it is, the more efficient the engine runs, as a rule (and to a point).

I would be interested to know if the guys that put the cooler thermostat in have seen a drop in mileage as well.


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## GTOtbird (Mar 4, 2006)

My mother-in-law swears that she gets better gas mileage with Shell. She lives in LA.


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## Justice (Oct 9, 2005)

My average is 16-18. I reset every month to get a feel for it. I have a pretty even balance of street and freeway driving.


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## jortegasr (Nov 4, 2005)

Are you guys going by what is diplayed on the DIC for your gas milage? I have noticed that it is not too accurate. When I first got my 05 I noticed about a 2 or 3 mpg difference. I average between 15 and 16 mpg when I figure it by hand.


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## 05NTEX (Mar 15, 2006)

8500 Miles on the car the very best all interstate from fort worth texas to tulsa ok in january very little wind set cruise at 75 up to tulsa averaged 18.9 none stop except for fuel just before tulsa which is a little over 300 miles. next day home drove the piss out of it anywhere from 75 to 110 and made 21.3. most of the time city driving get anywhere from 13.5 to 17 (SUCKS) my 7000lb diesel will do that o yea by the way the car was bone stock put exhaust, cai, and diablo on since runs better but same mileage.:confused :confused


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## 05NTEX (Mar 15, 2006)

not by the dic its off but miles divided by gallons of fuel


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## jortegasr (Nov 4, 2005)

05NTEX said:


> not by the dic its off but miles divided by gallons of fuel


:agree


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## HotRodGuy (Jan 9, 2006)

jortegasr said:


> Are you guys going by what is diplayed on the DIC for your gas milage? I have noticed that it is not too accurate. When I first got my 05 I noticed about a 2 or 3 mpg difference. I average between 15 and 16 mpg when I figure it by hand.



i've done the calculations, my unit is pretty dead accurate, sometimes off a few tenths


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## GTO TOO (Sep 10, 2004)

To answer your question of Why?? your gas mileage improved. No you did nothing !!! The answer is it's getting warmer. Engines use ( need ) much more fuel during warm-up to normal operating temps in cold weather. Yes, effieciency improves only so far as warm oil has less friction than cold oil. But once the engine and OIL are up to normal operating temps, the difference between Warm and Cold ambient is not as great of an effect on fuel economy as simple start up engine temperature. Cold fuel enrichment is the main difference between summer and winter fuel economy. Engines stay in an enriched state ( not only richer BUT RICHER LONGER ) as the temerature goes lower. That is the primary reason you get better fuel economy in the Summer vs. Winter.


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## C5ORGTO (Dec 30, 2004)

Thanks all. I thought it might have something to do with getting warmer. Its only up to 50 Degrees, but it is warmer. I thought I was going to be stuck at 12mpg forever. I live so close to work too(5 miles), I'm only on the highway for a short time, and those full throttle 0-60 runs don't help either. I was getting 16.5mpg in my Vette, so when I saw 12mpg on the GTO, I was a little bummed. (Yes the Vette is 500lbs lighter, and more aerodynamic, which is why it got better gas mileage).


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## MeanGoat (Jan 4, 2006)

Live in FL and have pretty consistent gas mielage winter or summer.

My question is: Did anyone with a CAI notice a _substantial_ increase in MPG when they installed their CAI? I go by the miles driven on a full tank in normal city-ish driving. Where I was getting 170-190 per tank before the CAI, I am now getting 210-230 miles. Been about 4 weeks and it's been consistent.

That's about a 1-3.5 mpg difference. Anyone else wanna help me hijack this thread?


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## jacobyb (Jan 2, 2006)

I'm at 19.6 right now. Not too bad considering it only has 2700 miles.


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## s2gordon (Dec 15, 2005)

MeanGoat said:


> Live in FL and have pretty consistent gas mielage winter or summer.
> 
> My question is: Did anyone with a CAI notice a _substantial_ increase in MPG when they installed their CAI? I go by the miles driven on a full tank in normal city-ish driving. Where I was getting 170-190 per tank before the CAI, I am now getting 210-230 miles. Been about 4 weeks and it's been consistent.
> 
> That's about a 1-3.5 mpg difference. Anyone else wanna help me hijack this thread?


I do all city driving in Orlando traffic...I get about 230-240 per tank full. I'm still stock, no CAI.


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## GOATGIRL (Feb 6, 2006)

s2gordon said:


> I do all city driving in Orlando traffic...I get about 230-240 per tank full. I'm still stock, no CAI.


I'm like you...getting the same 230-250 here in Jacksonville...I'm still stock too.


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## Mike_V (Mar 10, 2006)

According to my wallet, my MPG reading is dead on accurate. :willy:

I’ve come to the conclusion that, short of securing a surrogate driver, I’m stuck at  15. I’m thinking of putting a brick under the gas pedal. That should help my MPG.


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## MeanGoat (Jan 4, 2006)

GOATGIRL said:


> I'm like you...getting the same 230-250 here in Jacksonville...I'm still stock too.


Don't get me wrong, my dash says I'll get 250-260, but in reality when I check the trip it's what I stated earlier. I must admit that I am a rabid fan of the "take off as hard as the tires can still hold" methodology of driving.


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## 4 BKT VET (Mar 28, 2006)

I haven't had mine long, but I have been driving it like an old lady. I did notice that when I started "enjoying" the car, it seemed to improve. I am going to raise the RPM limit during my commute and see what happens; but not against the T/C limits.


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## 3RDGENGTO (Jul 30, 2005)

IM AT 17.2 RIGHT NOW.:cool WORST WAS 9.3:confused


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## [email protected] (Mar 20, 2006)

what would help is if you all posted gas mileage ratings with the type of transmissions. The a4 won't get nearly as good on the highway cause of the m6's steep overdrive.


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## Groucho (Sep 11, 2004)

I have more miles on the US-spec Monaro than anyone in the US....so here's the voice of experience.

2004 M6.

Given the profile of my daily commute:

Sea level - 4100' climb - Sea level, and some traffic on either end of my 230 mile RT daily commute, with an average speed of ~70mph. LA traffic kills the average speed- I drive the majority with cruise control set at 80 but long spurts at ~90+... and I make it a point to go over 100 mph at least once daily (weather permitting) for sanity's sake... :cool 

Taking the traffic out of the equation I can average 85 mph and still net 21 mpg; but stop - n - go traffic annihilates the average mpg in these cars. Throwing all of the above into account, I net an average ~19mpg.


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## fergyflyer (Apr 18, 2005)

There is a winter blend and a summer blend of fuel. The winter blend has more alcohol in it to reduce smog. The oxygen in the alcohol reduces smog theoretically. This worked 10-15 years ago when the car could easily be tricked into thinking there was a correct air fuel mixture. So in the cold weather when they set up too rich it leaned them out. Todays cars use the multiple oxygen sensors to track the air fuel mixture. When you put an oxygen rich blend in the computer just richens the mixture. Your mileage suffers instead of your performance. That's one reason mileage goes down in the winter.
The other is the warm up process. It takes about 20 minutes of normal driving for all fluids to reach normal operating temperature from 32 degrees. From 50 it is about 15 minutes. At 70 it is 8 minutes. The more you take heat out of the engine by running the heater the longer it takes. Untill you are fully warmed up, the oil is thicker and it takes power to overcome that. Also the fuel mixture is set up richer. 
The DIC fuel economy should be very close to accurate. The mileage is calculated by the computer using the sensors it uses to set the fuel mixture up. If the varience is large your computer is either setting your car up too lean or too rich. My was usually within a tenth or two. The gallons used was never off by more than a half a gallon, but there is variables there as far as how full you get your tank.


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## carbuff (Feb 7, 2005)

[email protected] said:


> what would help is if you all posted gas mileage ratings with the type of transmissions. The a4 won't get nearly as good on the highway cause of the m6's steep overdrive.


2004 M-6 here
BEST i ever got was in a caravan going to Bowling Green Ky from Nashville, in the fall, going 65 mph. I got 30.4 mpg.
seems with my NORMAL driving i get 17-21 City and around town interstate driving 24 - 25 mpg


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## JMVorbeck (Jun 1, 2005)

MeanGoat said:


> Don't get me wrong, my dash says I'll get 250-260, but in reality when I check the trip it's what I stated earlier. I must admit that I am a rabid fan of the "take off as hard as the tires can still hold" methodology of driving.


Heh, I was too until I had to put new tires on the rear at 6000 miles!


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## MeanGoat (Jan 4, 2006)

JMVorbeck said:


> Heh, I was too until I had to put new tires on the rear at 6000 miles!


Hell, you should have rotated them at 3,000. That's what I did.

When I took it in for the free oil change at 3K and asked them to rotate and balance the tires they looked at me like I had a leprechaun on my shoulder.

I had to re-assure them that I was not an idiot and yes, they DID need the rotate and balance. After closer inspection, they agreed.  

I got the "take off hard enough to spin 'em" methodology out of my system after I looked up new tire prices at the 3 k mark. I must admit it is creeping back into the gas operating foot again and my tires are showing the results lately....


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## TulsaGTO (Oct 3, 2004)

2004 m-6 with 4000 miles

I average between 15-16 mpg. Almost all of that is done in very spirited city driving.


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## ModBoss2 (Nov 13, 2005)

I maintain an over 23mpg average.


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## GTOooo (Feb 5, 2006)

Don't you have the 3yr/36k mile warrantee? The warrantee covers tires...


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## C5ORGTO (Dec 30, 2004)

GTOooo said:


> Don't you have the 3yr/36k mile warrantee? The warrantee covers tires...


Sure it does.


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## C5ORGTO (Dec 30, 2004)

FergFlyer. That was a good explanation. Most of my trips to and from work, are about 10 minutes, so my engine never really gets warmed up, hence the 12-14mpg average. I'm taking it on a 300 mile trip in May to hang with the Corvetteforum guys, we will have to see how it goes.


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## GTOooo (Feb 5, 2006)

C5ORGTO said:


> Sure it does.


So who cares how many sets of tires you burn through?


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## rrathea (Dec 1, 2005)

I used to average 15 in the city and 25 highway, but ever since I got the supercharger installed (larger injectors) I am now down to 12 - 13 city and 24 highway. I guess the old saying is correct "You want to play? You gonna pay!" :cool


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