Size and Shape does matter!!

RU2PED

Tremor Buff
Joined
Dec 31, 2020
Messages
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Location
North Carolina
Current Ride
2020 250 Tremor
Not log ago I posted about the differences I had towing my boat between the 2020 F250 diesel vs my 2020 7.3 Tremor long distances. I have since added an RV and wanted to update this as I have changed my mind on a few items.

The RV is a 2021 Forest River 41' with 4 slides with a guesstimated weight of 14k lbs. Dry weight is 12,600 and with what I have in it that's where the guesstimate comes from. With the results I had towing my boat which is about 9k lbs I was not looking forward to towing a 14k RV.

I towed the boat from Surf City NC to Ft Walton Beach FL and saw a whopping 7... MPG. Now ad I said on the prior post, the T-Top acts like an anchor with wind resistance.

Towing the significantly larger RV same route with about 5k more in weight I was shocked to see nearly 10MPG. More importantly the truck didn't seem to struggle as much as it did with the boat. I had the same headwind 20MPH @ 70MPH both times.

Originally I told myself if I bought a heavy RV or towed long distances I'd switch back to the 6.7. Well after this experience I don't think now I would make that change. I was pleasantly surprised how well it towed the RV and even more surprised how better it felt vs the boat.

Just goes to show you size and shape does matter. And yes my wife says same thing!!!
 

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I've studied aerodynamics and I find this rather questionable. The RV is clearly moving more air out of its way and it weighs a lot more. Something doesn't add up. We need to see wind tunnel data. ;)
 
I can see that! the 5er is got the nice cap and its tucked into the truck almost as a unit. The boat is way out there behind the truck in the air stream and the center console is just a parachute catching all the clean air off the truck and bogging you down.

nice toys by the way!
 
I'll tell you what, if I can get 10 mpg towing my 5er that weighs 2.5k less than yours, I will be ecstatic. I get 10 now with the Cummins.
 
Fuel economy should improve over time and level off somewhere from 15,000 to 30,000 miles.

Maybe the truck just wasn't broken in with the boat?

Also, pretty flat tow, so basically aero and rolling resistance.
 
Not log ago I posted about the differences I had towing my boat between the 2020 F250 diesel vs my 2020 7.3 Tremor long distances. I have since added an RV and wanted to update this as I have changed my mind on a few items.

The RV is a 2021 Forest River 41' with 4 slides with a guesstimated weight of 14k lbs. Dry weight is 12,600 and with what I have in it that's where the guesstimate comes from. With the results I had towing my boat which is about 9k lbs I was not looking forward to towing a 14k RV.

I towed the boat from Surf City NC to Ft Walton Beach FL and saw a whopping 7... MPG. Now ad I said on the prior post, the T-Top acts like an anchor with wind resistance.

Towing the significantly larger RV same route with about 5k more in weight I was shocked to see nearly 10MPG. More importantly the truck didn't seem to struggle as much as it did with the boat. I had the same headwind 20MPH @ 70MPH both times.

Originally I told myself if I bought a heavy RV or towed long distances I'd switch back to the 6.7. Well after this experience I don't think now I would make that change. I was pleasantly surprised how well it towed the RV and even more surprised how better it felt vs the boat.

Just goes to show you size and shape does matter. And yes my wife says same thing!!!

Have you done any suspension modifications to the rear? Do you know what the estimated TW is on your 5er?

The truck looks pretty good with the 14K 5er hooked up.
 
Congratulations!!! Awesome... curious to see mileage down the road.
 
I can see that! the 5er is got the nice cap and its tucked into the truck almost as a unit. The boat is way out there behind the truck in the air stream and the center console is just a parachute catching all the clean air off the truck and bogging you down.

nice toys by the way!
A submarine and a box kite?
 
A submarine and a box kite?
Exactly. The toughest pull I've ever dragged behind a truck was my 25' pontoon boat. Terrible aerodynamics, not that heavy, but wide and tall. Caught all kinds of wind and you could feel the turbulence going down the road. Irregular shapes do weird things in high wind situations. This is good news.
 
Have you done any suspension modifications to the rear? Do you know what the estimated TW is on your 5er?

The truck looks pretty good with the 14K 5er hooked up.
No its 100% stock. Pin weight shows 2100# slight sag in rear not much
 
Thats pretty surprising numbers, my 7.3 usually gets 8.5mpg with my 8K 32ft travel trailer and thats towing around 75mph. If I am babying it on flat land with no wind and 60mph I can get 10mpg, never seen higher than that.
 
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