1st tow 2020 F350 Tremor 7.3

[NASCAR9]

Let's get something out of the way first.
OUR 2018 6.7 DIESEL TOWED THE SAME 5TH WHEEL FASTER, LESS EFFORT, AND BETTER MILAGE.

Our truck is a F350 Tremor with 7.3, 4.30 gears, and 35” tires. Tow Haul mode was used for the complete trip. I Cat scaled our truck about a month ago, the trucks weight was 7220, truck and trailer was 18,460. I believe we were about 500 lbs. ~ heavier packed for our trip. 5th wheel is a 2020 Grand Design Reflection 303RLS.

Our tow was from Disneyland area to Las Vegas and back.

The trip includes a few climbs with up to a 6% grade. I could maintain 65+ on any grade coming or going. The gears used on our trip were 5th thru 10th. When I was in 5th RPMs were right at 4000 @ 65mph. At one point two semis were side by side going 40 up a long grade, after the semi finally over took the other semi and merged back to the right lane I floored the gas pedal and I was up to 65 in no time. I've never towed with a gas engine that pulled like the 7.3/10 speed. RPMs spread was about 350 between gears so it was like the truck was in the correct gear most of the time. When I wanted to force a downshift I just gave a little more throttle and the transmission shifted down a gear. Transmission temperature ranged from 208 - 228.

I wasn't worried about gas mileage on our trip. Gas mileage was 8.8 for our trip. Seems like we were always going up and down both ways, never really any long flat runs. I did watch the instant gas mileage display when the road was fairly level and saw 10-11 MPG at 65.

I believe the 35” tires didn’t help in any way towing, if anything it hurt performance and mileage. Standard 33” AT tires most likely would have towed better and returned better mileage.

[JColeman]

Why did you decide to go with the gasser after having the diesel?

[bertschb]

Thanks for sharing your experiences @NASCAR9 . I know a lot of people are interested in the new Ford 7.3.

[NASCAR9]

JColman,
We had a F250 with our tag-along and decide we wanted a 5th wheel. The pin weight for the F250 was 2395 so we needed a F350, about that time Ford started talking about the 7.3 to fill the gap between 6.2 and diesel. I always felt like the diesel was not even working hard towing our 5th wheel so I went on blind faith and we bought a F350 7.3. Another reason is my wife and I carpool to work and sometimes we take the truck, work is 6 miles away and the diesel wouldn't even be up to temperature by the time we arrive. I think the 7.3/10 speed will surprise a lot of people.

If we were towing 15k+ most likely a diesel would be sitting in my driveway.

[bertschb]

I'm not trying to scare anybody but folks may want to check the build date of their 7.3 truck to make sure it isn't affected by this...

[Txfivver]

Wow Brian I hadn't seen that one yet. We just got one yesterday on all 2020 Super Duty's built at Kentucky plant with build dates of 1-12-20 thru 1-14-20 that may have low rear axle fluid levels and must be checked. This is a no deliver no test drive until checked bulletin. Geez Dana, ship the axles with fluid in them will you?!

[NASCAR9]

I saw that bulletin and the axle low fluid on the Ford Truck forum, glad my truck was built in November.

[bertschb]

I saw that bulletin and the axle low fluid on the Ford Truck forum, glad my truck was built in November.

Oh man, that's good to hear!

[Bamaman]

Now that the 7.3 motors are on the ground and mpg figures are coming in, it shouldn't be too difficult to do a cost per mile comparison between the gas and the diesel F250/F350's. Bear in mind the diesels need the oil changed fairly often, and the 7.3 uses less oil in their oil changes. There's also a definite lower cost of gasoline vs. diesel and the gas engine is substantially less to purchase. Resale of the 7.3 motors should be improved over the 6.2's, but the intangible is how fast a diesel will sell on the used truck market (vs. gas.)

A few years ago, I did a gas vs. diesel comparison including real world resale prices, and in 5 years and 120K miles, the gas truck was about $3K less to operate after depreciation and maintenance costs. With the 7.3 motor doing the job it appears to do, that might be a fair trade off to save some bucks.

[Walaby]

Define diesels need oil changed fairly often. 6 months or 15K miles or 500 hours (for Cummins).

Whats a 7.3 frequency?

OP says diesel pulled his 5er faster, less effort, better mileage. That's enough to convince me to keep my diesel.

Although I will say not sure I care about faster.

Mike