I believe a stock truck identical to mine running 275/70/18 will get better mpg's than mine with the 35's. The size/weight/increased rolling resistance of bigger tires makes a larger impact than a few rpms on the NA V8 for mpg. The 4.30's just aren't as negatively affected by larger tires as the 3.73's are.
This aside, I really feel the 275/65/20 and the 295/70/18 are a great match for the 4.30.

 

How will your SuperDuty know you have larger tires? Are you going to program the Revolutions per mile into the PCM? If not, then MPG's cannot be accurately calculated, because the PCM is going to think you are still running the smaller OEM tires.

My point to get an accurate measure of MPG's is the PCM must be updated with the NEW tire revolutions per mile the Manufacturer provides.

the dealer NO longer is willing or able to update PCM tire size info.

However, it might be possible to get better MPG with the larger tires...dependent on speed and type of driving.


biz

 

I have a 2017 with a 6.2, 373. I just turned 1200 miles. On its first road trip with high way speed the whole way, i averaged 15.1 mpg. When I got home and was washing the truck, I began to wonder if the rather large air dam under the front bumper was limiting the MPG's. Has anyone experimented by removing the air dam to see if it became a little more aero dynamic and got better mileage without it?

 

Here is a picture of my new ride. I traded away a 2013 FX4 F150. Its amazing how much more truck this new 250 is!

 

The larger air dam was added to improve fuel mileage. I swapped mine for a shorter 2wd, but I added over sized tires around the same time, so I can't tell you the difference. Air going under the truck hurts fuel mileage. The air dam funnels it around the sides.

 

Congratulations and welcome to the club! In all of the mpg/air dam threads and posts I have read over time, the consensus is that they do help for mpg. I took mine off and I'm not really concerned if I lost any mpg's.

 

I would to see some in-cab video of a 2017 6.2 with 4.30s pulling a heavy trailer (10k+) up a decent hill. Don't need to see a mountain pull (I can already surmise that), but just a decent rolling hill, or even a quality overpass. Anyone????

As I'm sure you all have experienced, I continue to struggle with the gas vs. diesel debate for my next truck. Thanks in advance!!

 

If you're not scared to press on the gas pedal and let the 6.2L rev then the 6.2 can do it. The 6.7L will do it easier with less effort.

 

I have 1,500 in bed of truck.. and pull a loaded trailer at 9,500 pounds...

for a total rolling weight of 16,880 pounds. and my 6.2L has 150,000 miles...
and had done WV hills at 55 in second gear .. 4,xxx plus... rpms..

the 6.2L loved to spin and will ... but can you live with it doing it.????

I would like to Try a diesel.. but not in the budget.. same with a dually.

 

Sweet ride! I have the same truck in black!

 

I have no doubt the 6.2 can do it, and I understand how the gas engine makes it's power. I've towed fairly heavy trailers with gas trucks and after a while the RPMs just simply wear you out. But living with high RPMs in a 10 year old gas truck (or even just a few years old) is not the same as high RPMs in a gas truck built with today's technology. Today's trucks are quieter and the driver seems to be a bit more "isolated" from the engine's noise.

Then you add in the new updates to the 6.2 as found in the 2017 where the torque peaks out a bit lower in the band. Coming from a diesel truck myself, I now have a situation that may make the transition from a diesel truck to a gas truck easier. I just want to somehow get a feel (even if only virtually due to my present location) of how the truck does with the weight I'm likely to tow when I return to the States.

 

Well this thread was thoroughly hijacked by the 4.3 vs 3.73 arguments. Learned virtually nothing about the new 17's.

 

I don't know what the 6.2 sound or feel like in the 2017 but in my 2015 I had at 4k rpms or higher it was pretty loud in the cab as far as engine noise and exhaust noise. So even with all this technology you can't get rid of the V8 engine sound and noises. lol

 

 

There is a very busy 2017 SD section that is full of info.