Hello,

I am in the market for a new truck and have it narrowed down to the 2.7 and 3.5 ecoboost. My commute is around 40 miles each way to work with an average probably 45 mph. From what I've been reading the 2.7 seems to get rather better fuel economy compared to the 3.5 in real world numbers.. They both show quite close on the stickers of new trucks but apparently that isn't the case in the real world with people easily averaging 20+ mpg on the 2.7 and 17 mpg average on the 3.5, which is quite strange as the 3.5 shows 17 mpg city on the sticker.

Any opinions on 3.5 economy on say flat highway at 70 mph (crew cab 4x4 5.5 ft bed config)? I am guessing I would be fine with the 2.7 over the 3.5 but curious if there is really not a whole lot of difference mpg wise between the two.

Thanks

 

 

I noticed you have a SD with the 6.7, I take it you've been having issues with it?

 

I have the 3.5EB (supercrew, 4x4, 6.5' bed). My lifetime average is 18.3 mpg with about 34K miles on it.

In winter, I get around 17 in town and around 20 on flat highway at 70 mph.
In summer, I get around 18 in town and around 21 on flat highway at 70 mph.

I had a 2018 loaner with the 2.7EB for a week, it was a supercab XLT 2wd. It definitely got better mpg, but it was lighter (2wd vs my 4wd, supercab vs my supercrew). Going off memory, the 2.7EB in that truck was several mpg higher than my 3.5EB. It had plenty of pep. The only place I could tell a difference was when running 70+mph and hitting the gas...the 3.5EB definitely pulled harder. However, that should not be a surprise and it's not like the 2.7EB was a dog, I could just tell the 3.5EB pulled harder. Around town, I doubt I could tell the difference between the two engines performance.

 

Thanks for the info, this is exactly the type of info I am looking for from owners on here with these engines.

Your mileage seems to be pretty decent overall.

Here what fuelly shows for peoples averages with the 2018 and 3.5 EB config - 2018 Ford F-150 MPG - Actual MPG from 312 2018 Ford F-150 owners

You can see some people have 12-13 mpg average and some have 18+ mpg average, guess these engines can have a lot of variance because of peoples driving/towing habits..

 

My mileage is decent, but I'm conscientious of my driving habits. The distribution on Fuelly is a pretty good example of bell curve. So, once you ignore the outliers (hypermilers, hotrodders, and excessive idlers/warmups), what is left is that you'll most likely get an average of 16-18 mpg with the 3.5EB. Modify the curve for how you think you drive. If you feel you are more conservative than most and don't do long remote starts...you'll probably be on the higher side. If you idle a lot, have long remote starts, and short trips...you'll probably end up on the lower side. I live in the south, so that probably helps my mileage when you factor in temperatures.

Comparing the 3.5EB to the 2.7EB, the 3.5EB has its 4 highest peaks from 16-19 and the 2.7EB has its four highest peaks from 17-21 mpg. That tells us you should expect an average of 1-2 mpg higher average with the 2.7EB...which is about 5-10% better.
The 3.5EB engine is also a higher cost option, so there is another savings in favor of the 2.7EB.

 

Regardless if it`s the 2.7 or the 3.5, if you have a heavy foot, your mileage will suffer more than a NA engine.

 

 

Agree with what everyone said above.

I think this is the important part. The truck is the same size box pushing just as much air whether you have a 2.7 Ecoboost or a 3.5 Ecoboost . If all the other options are equivalent, you'll probably get slightly worse economy from a 3.5 doing the same job as a 2.7 . If other factors such as towing or hauling or etc. aren't a significant part of your equation then it seems the 2.7 would be a good fit.

I remember reading about an (I believe Ford-sponsored) event where they were testing 3.5 and 2.7 Ecoboosts and the 2.7 was faster 0-60 than the 3.5 by a small margin. It was long enough ago that I believe this would have been with the 6-speed transmission. Not sure if this is still true in later years with the new transmission. Trivia mostly, but reaffirms that the 2.7 is no slouch.

 

When I've looked at those comparisons, the 2.7 often had a 3.55 or 3.73 differential, and the 3.5 had the 3.31. Plus the 3.5 usually was in the heavier vehicle (like higher trim or bigger cab, or longer box, or some variation of those). If it were possible to configure two trucks identically with the exception of the engine, I have no doubt the 3.5 would win every time.

 

I would like to add a couple more things. I regularly drive both the 2.7EB and the 3.5EB, and they are real similar. There is no doubt the 3.5 is stronger, and slightly lower MPG. One area of difference is in engine braking. The 2.7 is bordering on useless in the engine braking department. The 3.5 is a lot better, but still not stellar. When offroad, the 3.5 in 4L will do a great job controlling your descent on a steep downhill. The 2.7 will almost be like being in neutral. Scared the crap out of me the first time I encountered it.

 

I believe the second gen 2.7 got all of these second gen 3.5 tweaks as well?


"The cam drive system changed from a single primary chain to a stronger two primary chain system with separate chains driving each cylinder bank. In addition to dual primary chains, the side plates on the chains were also thickened. The cam chain drive sprocket on the crankshaft is a double gear arrangement to drive the two primary chains. These two changes were done to improve the harmonics, and are also stronger to help minimize the chain stretch that occurrs over time on the 1st generation 3.5L EcoBoost.

The camshafts were made hollow for weight savings, along with the addition of a roller-finger follower valvetrain. The compression ratio was increased from 10.0:1 to 10.5:1 (except on the 3.5L EcoBoost HO for the Raptor, which remains at 10.0:1).

The chamshaft VCT (phaser) design was also changed to improve reliability and reduce the development of a tapping noise over time."

 

ahhh I read the oil burning bit and assumed you were sarcastically calling a diesel an oil burner, didn't realize you have a 5.0 gasser that is an oil burner!

 

Thanks for this..

 

'17 XL with some fancy options, 2.7, SCAB, 4x4. I am on Fuelly with just over 10,000 miles tracked. My average there is 18.6. The high was 23.1 on one leg of a long trip starting at 6700 feet, peaking at almost 9000 and ending at 240. Worst was 14.45 in lead footed all local driving.

For '17 they say:
Based on data from 608 vehicles, 22,291 fuel-ups and 8,406,501 miles of driving, the 2017 Ford F-150 gets a combined Avg MPG of 16.58 with a 0.05 MPG margin of error.

For '17 2.7s only:
Based on data from 143 vehicles, 5,321 fuel-ups and 1,865,599 miles of driving, the 2017 Ford F-150 gets a combined Avg MPG of 18.05 with a 0.08 MPG margin of error.

For '17 3.5s only:
Based on data from 321 vehicles, 10,433 fuel-ups and 4,204,602 miles of driving, the 2017 Ford F-150 gets a combined Avg MPG of 16.34 with a 0.06 MPG margin of error.

You can put in all the variables but I heard a yawn....