7.3 milege dropping

[Whata250]

I took another step. I went and had the stock muffler removed, and filled the hole with a straight pipe. I love the sound and look forward to seeing if that helps the milage.

I'm new on here..so be easy on me

If you just changed tires and went to a taller tire, your speedo could be off. The taller the tire the speedo will be slower and your calculation could be off instead of your mileage.

 

[CHPMustang]

I ran my speedometer against a GPS and found it was more accurate with the 285's over the stock 265 tire.

 

[Ken1]

I have 151K on my PSD and have averaged 15.2 MPG over the past 4+ years. That includes towing, idleing. 4 wheel and highway speeds. But in the last month I have been keeping it under 2K RPM and averaged 17.5 ~ 18 MPG

Ken

 

[Buddha43]

My experience is that the closer winter gets, the worse my fuel mileage is. Since I am near Chicago, it could be a cold weather winter blend?. Anyway, you will lose a bit of mileage with the tires, but they look way better. You have to sacrifice to look good!