Lousy Fuel Mileage

[RKamperRV]

We're on vacation and have towed about 600 miles so far. My fuel mileage stinks! I never got below 10 MPG before, and usually got 11 or 12. Now I'm lucky if I get 9.

My wife has noticed that her mileage in her gas mini van lately has been much lower, by 2-3 MPG. I checked with some other friends and they confirm that their mileage is also running lower than in the past.

Sooo...is the fuel industry tinkering with the fuel make-up in such a way that our mileage is suffering? Did the current federal administration mandate a different fuel mix to meet some new regulation?

I smell a fox in the hen house. Something is up and someone is hoping we don't notice.

[94-Newmar]

I notice decreases in mileage when they switch over to "winter" diesel fuel which is caused by the higher cetane diesel blends for cold weather. We don't typically see the winter blends around here in Ohio until November or so. I haven't noticed any oddities in fuel mileage this spring/summer though in either my Newmar motorhome (8.3C Cummins) or my daily driver 01 F350 SuperDuty 7.3 Diesel.

[RKamperRV]

I've gone over 2,000 miles now and am still experiencing very low mileage. I've talked to a few other drivers on the road and they are noticing lower mileage also.

[Wayne M]

Strange! Our 3 month trip so far has seen and increase in the MPG. Go figure.

[squeak]

this new d fuel sucks and has cut the MPG down and I think has even cut our HP down

[JoeT]

I keep fuel records on my PC for my TPDP Motorhome and my Jeep. I've seen no change in mileage for either one.

[RKamperRV]

I'm back from the trip. I drove 5300 miles in 2 weeks and experienced the same mileage throughout, but had no perceived drop in performance. I smell EPA in this...

[skigramp]

If you drove 5300 miles in 14 days that averages to 380 miles a day ... and at 60 mph that is over 6 hours of driving every day ...


From the records that I keep for my diesel motorhome I notice a 1.5 mpg drop when I increase my speed from 60 mph to 70 mph


Is it possible that you drove a little faster on this trip than usual ...

[RKamperRV]

Sure - but I experienced between 2 and 4 mpg drop in performance. I realize the higher speed contributes to lower fule mileage, but I have not ever experienced a drop of this magnitude in the past, regardless of speed.