Towing range 21” vs 20” ?

[Hyfly]

My truck is set to arrive first week of June. I’ve got the 20” AT and am aware of the range decrease compared to the 21”. I’m wondering if that is the same when towing a camper of if the trailer minimizes the difference.
would it be worth having a set of 21” for the camping trips/towing?
for example
21” range 328
20” range 274
Difference of 54 miles.

Now let’s say towing range with the 20” is 110 miles would I expect 164 miles with 21”? The same 54 mile difference.

I know there are a lot of variables and my numbers are just for reference sake.
thank for any insight.
I cant wait to get the truck in a few weeks!!

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[Redmond Chad]

The 21's will always be better. But towing a weight of x with drag y for a distance z on a given route will use a fixed amount of energy. That amount of energy will be a higher percentage of a more efficient setup than a less efficient one. One tiny benefit to energy inefficiency?

So the difference between 21" and 20" will be smaller when towing. How much smaller, of course, depends on many factors...so I'm not sure if that really helps you or not.

Things like weather and speed will make huge differences too. That makes it hard to plan on a set distance that you "know" you can make it. Be conservative at first, and over time you will learn what you are able to do safely.

I try to be conservative enough that I never get caught in a bind. But if you ever do: 1. slow down. 2. consider unhooking the trailer, go charge somewhere, and then go back to get the trailer.

Have fun!

 

[Electrified Outdoors]

Good answer given above. To put it in fairly simple and general terms towing a trailer, very generally speaking, will half your range. Sometimes you may do better and sometimes you may do worse than half.

Half of 328 is 164
Half of 274 is 137

So again very generally speaking the difference when towing is about halved as well. All of this will vary by the amount of weight being towed, the aero (big boxy trailer will do worse), weather conditions, etc.

Bottom line is that the more efficient setup when not towing will still be the more efficient setup when towing.

 

[blturner]

My take is that the tires take the energy they need and the trailer takes the energy it needs. However the extra force the tires have to generate to pull the trailer add a bit to the tire consumption. The rule of thumb that towing cuts range in half hides that. So the towing range improvement with the 21" should be a bit more than half as much as the range improvement while not towing. So in your example, instead of 54 miles better it would be a bit more than 27, say 30.

My experience towing is that 65mph vs 75mph will give me about 30 miles more range pulling my 16ft enclosed. And the dashboard range estimate is not super useful while towing. My range towing at 75mph is about 40% of normal. If I slow down it is about 55% of normal. But that is not scientific.
BTW, I have 21s

 

[azbill]

I did a towing test with 21" on my R1T, pulling my 5500lb boat. Could only get 115 miles at 70mph. I doubt the 20" tires would make much difference. There is no way the difference is a constant of 54 miles. The only way to get more range is to slow down. The tire difference is probably more like 10 miles.

I pulled my much smaller 8x5 enclosed trailer with single axle, and it was getting 175 miles.

 

[Electrified Outdoors]

I am going to be doing a lot of towing range testing very soon with my Apex 245BHS ultralite. That travel trailer is about 4600 lbs dry.

 

[Hyfly]

Thanks all. I was assuming the difference towing would be minor 10ish miles. But hoping for more.
Sounds like the expense of the extra set of 21" tires would not be worth it in this case.

 

[Eeyore]

Thanks all. I was assuming the difference towing would be minor 10ish miles. But hoping for more.
Sounds like the expense of the extra set of 21" tires would not be worth it in this case.

Or you could just replace the 20" AT tires with 20" road tires and get some range back.

 

[kizamybute']

Or you could just replace the 20" AT tires with 20" road tires and get some range back.

Go down to a 275/60/20 and the tire size will be the same as the 21's or 22's as well. The 20" wheels have a 34 inch tire while the 21's and 22's or 33 inch tires. A 275/60/20 is also a 33 inch tire.

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