FLA-SVT

11.5 city all day long....The highway is completely speed dependent....anywhere from 14-17 depending on speed. not sure why the 2012-2013 are rated better than the 2011 for fuel mileage, but mine said 14mpg highway on the sticker

HoustonRider

a tank avg for me tended to be 11-13. The best I got was 15 mpg on a long trip.

You can drive 60 mph for the best mileage, but thats 15mph under the limit here in Texas.

13Raptor

I've only run through one tank which had ALOT of idle time with the dealer doing that MyFord Touch review ****.. (30+ minutes) and showing off the features to friends.. that tank was 13.2 mpg.

I'm on the second tank now and the dash is reading right around 13.5 mpg.. on the hwy I'm seeing right around 15mpg @ 70mph, but when I do my short 1-2 mile trip for lunch or let her warmup in the morning waiting for my son's school bus it really kills the mpgs.

yokev

My Ecoboost(4wd) has 315/70/17s, and while I never understood why people would want a truck that gets such horrible mileage as the Raptor, I HAVEN'T even seen where mine bottoms out. I keep re-setting the fricken gauge when it gets into the low 10s because I'm pulling my(last) hair(s) out by then. I have 3.73s, and the thing certainly isn't lacking for acceleration or power, but for whatever reason the E-boost motor starts gas-bonging when you put bigger tires on it.
I personally need a bigger bed than the Raptor comes with, so it still wouldn't work for me, but it's truly AMAZING what happens when you get vehicles out into the real world.
I would KILL for a 13mpg average. KILL for it....

JLonsinger2011

Well if you put those big of tires on any truck, you'll get worse gas mileage. That's a common sense given. As for the remark "I never understood why people would want a truck that gets such horrible mileage as the Raptor", are you serious? Who the **** buys a truck for gas mileage? You buy a Raptor for the offroad ability and all around badassery.

HoustonRider

I have 3.73s on my ecoboost with stock 20" rims and tires. Last week I stayed in Houston, freeway, city, etc and got 565 miles to a tank, and 18mpg. That's 5 days of driving in all kinda traffic.

I stayed easy on it and kept it 60-70 ( almost never 70) and saw those numbers. My fill up said I had 610 miles to empty.

yokev

Firstly, your reading comprehension needs work(so does your sentence structure), as after reading my entire post, you should have understood that the POINT I made was that REAL mileage is often DIFFERENT than CLAIMED mileage.
The Raptor does better, and my truck does worse.
But I would like you to tell me how much worse the mileage on the Raptor is from running 'those big of tires'...?
As I STATED in my post, I'd KILL for the Raptor's mileage.
Other trucks that don't get horrible mileage are diesels. I've owned 6 of them since 2001, and every one of 'em gets/got 16/20+ running 35/18's.
Hell the GM 8.1L got better mileage than my Ecoboost running the same tires.
Same with the Ford and Dodge V-10 and the GM 6.0L
Since my point was NOT that trucks get 'worse' mileage from adding 'those big of tires', but questioning how much 'worse' mileage a truck SHOULD get from adding 'those big of tires', your post is MOOT.
Have a nice day anyway..

WarSurfer

The Eco benefits greatly from gearing. The Eco 'Raptor' gets 1-2 mpg better than a Raptor and its on 37's - because its also running 4.88:1 diffs.

The Eco only gets good mileage when not in boost, under load its operating as a 7liter (effective displacement {3.5l @ ~15psi max = 7l}). To keep the Eco out of boost with the larger tires, increased front profile, extra weight, etc.. you have to increase its mechanical advantage (towing, hills, hard acceleration).

Obviously there is a point of diminishing returns, at some point you can have too low a ratio and you'll be decreasing mileage because RPMs will be too high.

If it were me, I'd figure out which Eco variant (gearing wise with whatever truck configuration you have) gets the best mpg, then I would do the math to figure out what ratio I would need to achieve an equivalent final ratio given the larger tires - I bet you get your most if not all your MPGs back.

Ex: factory ECO SCREW 4x4 3.73:1 on 265's gets XXmpg

Lifted ECO SCREW 4x4 x.xx:1 on 35's needs (4.56 / 4.88 / whatever) to have the final ratio equivalent as the final ratio for the 3.73:1 on 265's.

yokev

4.56's et al. would be WAY overkill.
With 3.15s, it's only 6% or so taller than stock(3.73 x 32.2" tires), and the 'required' ring and pinion to return it to the stock F.D. would be under 4.0. Not many options between 3.73 and 4.0, plus it's not a very big gap. We're talking under 500rpm here.
In any event, me personally, I'll just pitch it in a couple years and prolly go back to diesels.
Back to the original topic>

WarSurfer

I was using those ratio's as an example. The Eco has proven (by the nature of how it makes power) to be very mpg sensitive to added weight, larger tires etc. 4.10's would probably be right in the sweet spot - according to your math above and given the ratio options.

As I posted earlier, the Eco Raptor gets a solid 16mpg avg on 37's - it has a tune obviously but it is also geared appropriately for the tires and added weight.

http://youtu.be/wYWE11Oo5rg



OT:
I just swapped to a more aggressive tread and I dropped from 12.6 to 11.5 combined avg.