# Trailer Length Vs. Wheelbase. The Old Calcs Don't Seem To Work Anymore.



## thefulminator (Aug 8, 2007)

My wife and I went to a local RV show yesterday, just to see what's new. We found a "some day" trailer that we really liked that would be way more than our 2009 Silverado 1500 would be able to tow. I plan on either a 3/4 ton or one ton for my next truck but the new trailer made me start to think about what would be required to pull it.

The historical equation I have seen in multiple places for trailer length vs. wheelbase is 110" of wheelbase for 20' of trailer length. For each additional 4" of wheelbase you get an extra foot of trailer. My current truck has a wheelbase of 143.5" which per the formula allows a 28'-5" trailer. Our current trailer is 27'-9" long. I've never had issues with the combination.

The trailer we found at the show is 37'-11". Using the equation, the truck would need to have a wheelbase of 182". I took a look at the 2019 Dodge, Ford and Chevy brochures. The longest wheelbase that any of them offer is a Ford at 176". Most are in the 140"-170" range. So my question is, has a new method for the length to wheelbase calculation come out or does it just not apply to the larger trucks?


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## Dave-Gray (Jul 9, 2012)

Actually, you have discovered the reason that old calculation method has mostly been eliminated a long time ago. Unfortunately, there are still a few remnants of that formula floating around the internet.

First and foremost, read the vehicle's owner's manual towing section. Some manuals warn not to tow a trailer when the trailer's frontal area exceeds a specific square footage. Most truck manufacturers use SAE J2807 towing test standard for publishing the GCWR and the TWR for each vehicle. However, these ratings are specific for the truck at its base weight and configuration. It is important to learn what the tow ready realistic vehicle towing capacity (RVTC) is for you only. Just because someone else may have been towing something successfully does not mean you can do the same.

It is a bit more difficult to learn the RVTC when shopping for a new truck but with careful estimation and knowing the weight of the tow-ready truck, you can obtain good RVTC to ensure you will not exceed the truck's weight safety ratings. Most of the time, the RVTC will prevent one from buying a trailer too long.

Additionally, having the best quality and properly configured hitch assembly will help with safely towing trailers that appear to be too long for the tow vehicle. Sometimes, one will need to back up the tow vehicle to the trailer tongue and take a good long look at it. If they have any doubt about the safely of towing that trailer, then they shouldn't buy it.

Here is an article that may help you prepare for the search for the right tow vehicle: My Truck Pulls It Just Fine, Truck Buyers Beware


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## Oregon_Camper (Sep 13, 2004)

Wheel base....

Towing....

Now for the fun part...What new trailer are you looking at????


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## thefulminator (Aug 8, 2007)

Not really looking, just daydreaming. Thinking of the day when we won't have kids in tow. It's a Grand Design Reflection 315RLTS. We have seen similar models from other companies but this one has far superior storage than the competition.

Sent from my VS988 using Tapatalk


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