Im a little confused with my 2015 2.7 ECO, have had it a little over a month,first tank of gas I got 20.5 mpg second went up to 21.5 all kinds of different roads,took a trip to New York all freeway and mpg went down to 19.5,I know it still needs to brake in but worse mpg on the freeway??

 

My 01 King Ranch on 31"s and a 3" body lift gets around 12.4mpg.

I'm thinking about getting a bed cover to help with gas mileage.

I also probably need a new air filter and definitely need an oil change this week. I hope those 3 things can help a little. 15mpg would be nice!

 

Bed cover (soft - Truxedo) didn't help my mileage at all. Didn't hurt it a bit either, though. Worth a try if the cover is something you'd use anyway.

 

Many people automatically think the smaller EB engine will provide better mileage. Yes and no. The thing to remember is that under exactly the same conditions, the 2.7 will have to work harder to provide the same output as the larger 3.5 EB or the 5.0 V-8. As a result, the 2.7 will spend more time with the turbo running than the larger engines. As a result, the decreased mileage at speed.


That said, on a light load, yes, the 2.7 will get better mileage than the 3.5 or 5.0. The differences all come into play under load. When power is needed both of the EB engines do put out a lot of immediate power. But do you need that capability all the time?


Check and make sure your air filter is clean. You might try increasing your tire pressure to 5psi over the sticker specs (not the tire max, the door sticker). This allows for a little less rolling resistance. I also use nitrogen on mine. Some like it, others feel it's a waste; it's a matter of preference. Be light on pedal pressure when accelerating and coast when feasible as you approach a stop. Drafting, though a good technique for saving gas, can be extremely dangerous. Plus it tends to **** people off. When it comes time to get new tires, look for Low Rolling Resistance tires that are suitable for your truck. However, though I like Michelin overall, don't get the Michelin Latitudes. They are LRR tires and well suited for cars and light vehicles, but suck when applied to a truck that gets used like most of us do.


Hope these tidbits help. Let us know how it progresses.

 

good advice, and he didn't mention what speed he was doing on his highway trip. even so, he still beats most of the 2.7s on fuelly.

 

Wow...I have a 2013 FX4 5.0 SCREW, 3.73 gears. I had the stock Pirelli 275/55R20 all terrains on it. Just put a 3" Icon coilover leveling lift on it with Method 17" wheels and 35" Toyo M/T's. Looks great but the mileage went all to hell. I was expecting a fair drop but for a few months all around city and highway I was averaging a very consistent 14.2 mpg. It's only been a couple weeks but my average has dropped to around 10.8. I'll give it some more time but don't see that number changing much. Driving style hasn't changed. That's about a 3.5 mpg drop! Keep checking under the truck to see if I hooked onto a boat anchor somewhere. Maybe I'll trade this thing in on a 6.2 Raptor so I can get into something economical.

 

Or regear and get it back to stock ratios.

 

If I may, a few things to consider, since I have a 2011, same stock configuration. Unfortunately, it may be moot, since you've already made the mods. Anyway, 1- the lift/leveling kit affects the airflow around the front end of the truck. When Ford designed their trucks, much of the airdam installations were not for esthetics, but for smoothing the airflow, thus improving mileage. 2- Check the overall diameter of the Toyos you've installed. If that diameter is larger than the stock Pirellis, mileage will decrease, However, part of that is a measuring issue. If you can, get a radar speed check at varying speeds. Many of the Highway Patrol offices will assist you in doing this. Ensure your speedo reflects the correct speed or make yourself a compensation chart, so you can get accurate speed readouts. Additionally, oversize tires will affect the computer, odometer, and power requirements to get to the same speed, again affecting mileage.


Hopefully, these items may help a bit in getting accurate figures. Let us know how it progresses. Good luck.

 

Thanks.....I understand the tire diameter, wheel and tire weight as well as aerodynamics change, I just wasn't expecting this much drop in the mpg. I've always had lifted trucks with oversize tires...typically 8" lift with 37" and even taller mud terrains where a big drop in mileage seemed more justified. I typically just left the speedo calibration alone and figured I'm going about 10% faster than it says. I wouldn't mind getting the speedo calibrated this time as I'm sticking with this tire size but I don't know how extensive that is. The new tire is exactly 5.5% taller. Anyone know if that's close to the speedo difference? Don't know how to figure that but it has to do with circumference.


My stock tire was spec'd at 31.875 high but I believe they usually measure shorter. My new 35" tires are not brand new (70% tread left) and they actually measure at 33.625 high. Using a tire size change calculator it gives me 3.96 gears for stock ratio and probably not worth the gear change from 3.73. The 4.11 gears are closest and even closer if the tires are new and about 1" taller but I've done the re-gear on other trucks in the past and haven't felt like it improved my mileage.

http://www.4lo.com/calc/geartire.php

 

Sounds like you're digging into it carefully. Getting your speedo is about as easy as it gets. The local HP folks will have you, either on the road or on a dyno, go to different speeds: 50, 55, 60, etc., based on what you are seeing on your speedometer. If on the road, they'll either pace you or have you go by a calibrated radar gun, which will provide what they will see (better option for road driving). If done on a dyno, same thing, but they get the readout off their meters (more accurate for technical uses).

If there's a speed shop in your local area that does full rebuilds, they often have their own dyno where you can check and calibrate and, perhaps even more important, run an output check and tell you how much horsepower you're actually putting out, both at the engine and to the ground.


As to gear ratios, as you've already learned, mileage does vary, even with the same tires, by gear ratio. You are probably already aware, but just in case, the higher the numerical ratio (3.91 vs 3.73), the better the torque for pulling power and acceleration. Unfortunately, it also means lower mileage. A lower numerical ratio (3.31 vs 3.73) will give you better mileage overall (with a few exceptions), but it also takes longer to get up to speed and you can't tow quite as well, particularly uphill.


There are some other ideas I've sent forward to folks on the forum that I found worked well for me, resulting in Highway mileage in the mid-20s, and just under 20 while towing, and my city mileage is still averaging in the high 18 range. I also replaced my tires, but didn't go with as large as you did.


Good luck and I hope some of this is of use. If there's anything else we can do to suggest improvements, be sure to sound off.