Not that I'm complaining, but my milage shot up significantly about four tanks ago. It's up to 23.0 mpg. Granted, this has been 95% highway driving. The first two tanks I was driving between 60 to 65 mph, the third tank was right at 65 mph, and the fourth at 70 mph. I do drive for milage (shift at or below 2000 rpm, etc.), but really don't understand why the milage suddenly shot up. Before this, my truck was getting 20 mpg. The only thing that I changed was teh air filter (stock filter just put in a new one from AutoZone - DuraLast brand ???). Could this be it? BTW, my truck has 40,000 miles on it.

For all you non-believers, I have kept track of every ounce of fuel that my truck has consumed since day one. The last four tanks were consecutive - 2718 miles w/ 118.0 gallons consumed!

 

Better check that air filter for Great Big Holes.

 

If a better or no restriction filter is all it take to get that kind of mileage then why didn't mine with a fan pushing air into the motor? I never had negative air flow, positive flow most of the time.

 

My guess would be it is a better quality of diesel fuel.

 

That's exactly what I thoght on the first of the four tanks. Even the second. But four tanks in a row? I've been driving alot lately (the 2718 miles came on in the last 2 weeks), so we have been out of winter fuel for a while. Also, I have fueled up in four different places & 3 different states (VA, OH and NY). I slowed up a little (averaging 65 instead of 70) but the speed alone does not explain the 15% increase in milalge.

 

If it's really that bad I'll buy your truck and you won't have to worry about it. My guess is you got one of the exceptional trucks that the odomiter is off some or a lot and you go less miles than it shows so it gets great mileage. Or maybe the computer is messed up and actually letting the motor run at its optimum effeciency. Man if someone could use your truck for a test vehicle and then set everyone up like yours.

 

First of all, I'm not complaining - I really cannot believe it. I used to get 20 mpg in the summer (i.e. summer fuel) before the last four tanks.

Second of all, the calculation is hand calculated and based on the odometer. However, it is 'confirmed' by real distances travelled - been from bouncing back and forth from VA to Ohio as well as going up to Boston.

I'm not trying to convice anyone of anything, but do know that my data is accurate & real.

 

It might have finally broke in.

 

Would you mind telling us the mileage on your truck?

 

It's right at 40,000 miles. I've not really worked it - towed a trailer a couple of times but not regularly. Like I said, the milage just jumped up all of a sudden (four tanks ago). It's always gotten what I thought to be good milage - 20 mpg if I kept it below 70 mph, but four tanks ago, it went up to 23. I do drive very light footed, but still, this is unbelievable milage. Someday, I'm sure it will go down, but I'm enjoying it while it's there.

I only did one mod - the tone ring mod to advance the timing. This was done 20,000 miles ago. Seemed to help milage, but only by .5 mpg or so. Other than that (and the 315 tires - which was a break even prospect from a mpg perspective), my truck is a stock 6 spd. 4X4.

 

I bought my truck used and it still had the original factory filter in it. The minder was pulled down about 1/4. I put in a new Wix filter, with a higher flow rating, and swiss cheesed the air box. My highway mileage went from 18 up to 20 mpg with this change. So yes, I think a better flowing filter may have helped you. Was your minder pulled down any before the change?

 

Yes, it was about half way down.

 

That was it then! I'm not an engineer but have you ever tried to push that filter minder down? Its not bedspring stiff but its not ballpoint pen easy either. It must take a lot of vacuum to pull that amount of tension down.

 

Dumb question, but what's teh filter minder? I'm new to this diesel stuff, so bear with me. Thanks.