On my weekly trip from Atlanta to Knoxville last night I decided to find my sweet spot for best mpg. The trip was 192 miles, some good hills with very few truely level stretches on I-75 northbound. I started out at 65mph set on the cruise control, watched my onboard computer and finally decided to run at 58mph at approximately 1600 rpm. I AVERAGED 25.5 MPG!!!

This is with Power Service additive added at 1/2 oz per gallon of diesel. I average 21.8mph @ 70mph on the same stretch of road.

I am wondering if I change my tires back to the original 265's, put in a bhaf, and add a 4" exhaust if I can improve this by about 3-4mpg?

 

do yourelf a favor, switch the overhead to display outside temperature, its better off telling you when it is warm enough to roll down the windows than it is at telling you your actuall mpg, go back and try another trip, even if it is only a hundred miles and then hand calculate the mpg for a real result. just one mans humble opinion that happens to be shared by many.

 

Sometimes the added turbulence with the windows down makes more drag than with them up and the A/C on. This is especially true if you have an aftermarket A/C which cycles the compressor on/off when the temp inside is cool enough. Some factory A/C systems just run the compressor all the time and mix warm air from the heater core to regulate temp.

What???

Edwin

 

That's pretty funny! But my overhead console actually seems to agree with my hand calculations. Cant you guys get good mileage?

 

miens always the same off, always .8, not that i depend on it BUT it is good to see where the mileage goes pu and down at, it might be 5mpg off, but if it reads higer or lower its still telling the truth there..... usually

 

My overhead runs close as well. It does its best when towing the fifth wheel.

68 is my sweet spot on the hwy without really slowing down. Runs around 19mpg. Slower, of course is better for mileage. When running in a lot of traffic for a long distance, the mileage indicated will be way up. This is due to the traffic breaking up the head wind.

Another factor is fuel. I once filled up outside Wilmington, NC and drove to Scanton Pa without fueling. That was a good tank of fuel. No additive with that tank. I use additive with every tank for the past 3 years.

158K Original VP44. I found some wood.

I've heard the 2003's and up are really out as one of the posters here indicated.

The function I have in mine, which some don't have, shows mileage as you drive and not an average, the average mileage is a seperate function.


Dave

 

my overhead says 25.8 and i actually get 17.4 dont trust em!!!

 

Now my 99 only has the average, a friends 01 had the "instant" mileage and my brothers 02 gasser had that, I thought my 04.5 would have it but nope back to average, i want instant darn it haha

 

I've gotten as high as 26.8 and 26.4 on 2 different trips last year. Most of the time I get around 23 though. I always use hand calculations. My best mileage is running around 60.