glittauer

Sorry I haven't checked back in in awhile. Thanks for all of the replies. I'm getting 19 to 21 overall mpg when not towing, so that's a big improvement. Like a couple of you said, the mpg when not towing more than makes up for the 9-10 mpg when towing. Guess we'll see how it goes from here. Thanks again for the help.

Siskiyou

I have gotten up to 11 mpg towing a 6500 lb. trailer on flat ground. Keep in mind how much extra power you have now over your 5.4.

chimmike

we did get about 1mpg better towing @ same speed with the same travel trailer, in arguably higher temps here in FL a couple weeks ago versus our first trip with the truck when it had ~800 miles on it.

Also, I would suggest an oil change at 4k miles. I could smell the fuel in the oil (normal for direct injected cars), so I'm not convinced a 6k-8k interval is a good idea.

I went with Castrol Magnatec in 5w30 as recommended at BITOG.

glittauer

Thanks. I just did its first oil change at 4300.

Fwonfiddy

I must be the odd one out. I'm getting a good 19+ daily driving (probably 70% highway) and on the couple of 200 mile runs I've done I'm getting 15+ towing 7500lb.

I have the 10 speed if that's a reason?

johndeerefarmer

What are you towing? A flatbed trailer full of pipe or something else with no wind resistance? Or are you driving 55?

Having towed a 10k fiver, a cattle trailer weighing 6k, a 24' aluminum flatbed with two RZRs on it, and a 12' utility trailer with a RZR on it the only way I can get 15 mpg is to pull either my 12' or 24' trailer empty with nothing on it. The wind resistance is what kills your fuel economy, that and hills.

For the OP; try a tank of premium. I run it all of the time because I tow and it's hot here. See if you get any fuel economy increase from it as it gives you an additional 20HP/10 lb ft which might let you run in a higher gear

Fwonfiddy

35' travel trailer - I know I know - it's too big for my truck. I don't go above 60 and sit around 55 because I feel comfortable at that speed. I use regular no premium. I don't use tow haul mode unless I'm going down a steep hill.

SkiSmuggs

With my 2011 3.5TT, Ford recommended premium for both summer and towing, plus they recommend Top Tier http://www.toptiergas.com/licensedbrands/ gas at all times. I am sure that is still the case. With premium top tier, I got about 10-12 mpg towing my 10K fifth wheel.
One winter, I started using regular non-Top Tier and was bummed by the poor fuel mileage. Mobil had an offer for their credit card I couldn't pass up and switched to premium with it and gained 1.5 mpg in my daily commute. I never went back to El Cheapo.

Fwonfiddy

ford recommends regular for their 3.5 eco - it's an eco so works without premium fuel

jcb206

It does work without premium fuel. But they still recommend Premium for best best performance during towing and hot temperatures. In your manual.