What's your highway gas mileage ?
Platinum Member
Joined: 12-06-2009
Posts: 11,718
From: Alabama
OK there are two differences I see.
You don't do short runs and the GM tune upgrade was a plus.
If I turn on my Trifecta tune mileage doesn't increase.
I know the ECM learns your driving habits. In your case your mostly "highway" and it has taken that into account for possible better mpg ?
George do you reset your mpg on the DIC everytime you fill up ?
You don't do short runs and the GM tune upgrade was a plus.
If I turn on my Trifecta tune mileage doesn't increase.
I know the ECM learns your driving habits. In your case your mostly "highway" and it has taken that into account for possible better mpg ?
George do you reset your mpg on the DIC everytime you fill up ?
Thread Starter
Senior Member
Joined: 08-03-2010
Posts: 3,564
From: Lake Ronkonkoma, N.Y.
Car runs great. There's got to be a reason.
Always use premium, tires are inflated correctly, drives straight and no performance issues.
The only thing I have to check is the air filter now that weather is warming up. But I can't see a filter being that dirty to have a vast mpg difference. I mean if it was that bad the car woundn't run as good as it does.
Senior Member
Joined: 09-07-2008
Posts: 1,016
From: Mebane, NC
Senior Member
Joined: 09-15-2013
Posts: 406
From: Cleveland. Ohio
That's two that get better mileage than me.
Car runs great. There's got to be a reason.
Always use premium, tires are inflated correctly, drives straight and no performance issues.
The only thing I have to check is the air filter now that weather is warming up. But I can't see a filter being that dirty to have a vast mpg difference. I mean if it was that bad the car woundn't run as good as it does.
Car runs great. There's got to be a reason.
Always use premium, tires are inflated correctly, drives straight and no performance issues.
The only thing I have to check is the air filter now that weather is warming up. But I can't see a filter being that dirty to have a vast mpg difference. I mean if it was that bad the car woundn't run as good as it does.
Senior Member
Joined: 09-07-2008
Posts: 1,016
From: Mebane, NC
Not in the same sense of say a carbureted engine. Crude explanation, Mass Air Flow Sensor measures amount of air coming in (grams/sec) and fueling is then determined by that and what the wideband O2 sensor is reporting on an SS.
There are a number of cross checks based on throttle position, rpm, map sensor that will compare what it should be seeing for air flow and if air filter is blocked/air flow is low it will throw a code long and go into limp mode before it effects anything drastically.
There are a number of cross checks based on throttle position, rpm, map sensor that will compare what it should be seeing for air flow and if air filter is blocked/air flow is low it will throw a code long and go into limp mode before it effects anything drastically.
Thread Starter
Senior Member
Joined: 08-03-2010
Posts: 3,564
From: Lake Ronkonkoma, N.Y.
OK mystery solved.
Cleared the MPG and average MPH on the DIC. Reset the trip odometer also.
Took a ride to a friend's house 22.5 miles away.
On the expressway the traffic was good for a little bit and then bottleneck stop and go. Got onto another highway and traffic was good.
I got 19.1 mpg and average speed was 15 mph.
On the return trip traffic was better and I got 26.7 mpg and average speed was 43 mph. Again I hit some stop and go but not like in the morning.
Both times cleared info on the DIC.
I never clear this info and thought the mpg that I originally showed (18.1) would have changed as I drove highways, I guess not. If it did it was in small increments.
Cleared the MPG and average MPH on the DIC. Reset the trip odometer also.
Took a ride to a friend's house 22.5 miles away.
On the expressway the traffic was good for a little bit and then bottleneck stop and go. Got onto another highway and traffic was good.
I got 19.1 mpg and average speed was 15 mph.
On the return trip traffic was better and I got 26.7 mpg and average speed was 43 mph. Again I hit some stop and go but not like in the morning.
Both times cleared info on the DIC.
I never clear this info and thought the mpg that I originally showed (18.1) would have changed as I drove highways, I guess not. If it did it was in small increments.
