I couldn’t be happier with the mileage I get on my 2020 Lariat 6.7, SWD, 3.31, 10-speed. I actually posted pics of the 25mpg trip (about 100mi) at speed limits 60 and 65. However realistically driving Hwy speeds about 21 empty, 16 in town, and about 10 towing a 12k 5th-wheel depending on speed and wind (I’ve seen as low as 8 and as high as 13 depending…). Biggest factor - the weight of my right foot.

 

15-19 get lower mileage ( more fuel/ power) than 11-14 and the new 10 speeds.

 

2019 CCSB 4x4, 3.55 all stock on stock 275/65 20 tires. Unladen mostly city driving I get 14-15 mpg, sometimes less, never more. All highway, average 70 mph with only a couple passengers and some personal belongings the best I can get is 19 mpg on a tank. I would call it 17-19 highway. The 2020+ trucks seem to be able to get about 2 mpg better, I attribute that to the 10 speed trans.

 

Agree with 84flatbed about the 10-speed, but I also think the 3.31 rear end probably also contributes. A little less power to the wheels, but a little more mileage on the road.

 

I'm clearly learning the nuances here...

If I read these messages correctly, the 17-19 models use (exclusively?) 3.55 diff ratio, and the 20+ use (also exclusively?) 3.31? If my interpretation of this is accurate, I'm assuming this is because the 10-speed has a lower 1st gear than the 6? I was under the impression (now I need to verify this) that the high gear was very similar in both the 6 and 10-speeds.

Thank you for your replies, would appreciate it if others could add as well. Looking for the biggest cross-section to help with my decisions. Thank you all,
PE

 

Checked the data in Fuelly.com ?

 

I am getting 13-14 MPG empty, and 6-8 with the 42" 5th behind me.

 

My "17 F350, mostly stock....avg 15-16 city and on long interstate road trips can reach 21 if keeping 70-75. Also use hotshot secret EDT, which seems to assist. This is my DD too.

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My 16 250 is getting around 13.5 mpg in the city and 18-19 mpg at 75mph. Towing our 33 ft TT I would get 10-11 mpg.


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Any experience with 2017-2019 F450 vs 2020+ F450. All 450's have the 4.30 axle ratio. With the 10 speed and gen 3 6.7, I'm curious on what the real world difference is. I'm looking to get a 19 or 20/21 for my next vehicle here shortly. Looks like about 10k difference between a 19 and 20. I do plan on putting either on a diet shortly after getting it with a conservative heavy tow tune. Thank you in advance!