Towing Limit for 4 cyl much lower then 6cyl - based on engine size or other shortcoming of truck

I bought a 4cyl Tacoma when I just owned a jetski but now I am looking at a small boat that is only a bit over the rating of the 4 cyl model.. I was already wondering how this rating was determined and then Jason from Engineering explained did a really good on the J2807 standard. He explaned the set of tests that are run and that basically the truck is rated for the highest weight that passes all the tests.

I was wondering if there were any reports about the limiting factor for the 4cyl. Ie what test fails the 3500 lb weight. Could it be a test that is related to the the brakes, or something else that can be upgraded - ie a better hitch bolted to the back, better cooler etc. Obiviously the engine size is a factor but was wondering if anyone knows if the results of the J2807 tests are published so I can see if there is another part in the equataion that is pegging the limit lower.

In my case, in 99% of the boat use cases I would be towing the boat down a 25mph road for 1 mile as the ramp is right near my house so I can likely push it a bit without any upgrades. But I am willing to take some steps to make it more tow worthy if there is an opition.

Anyone know if the J2807 test results are available online?

Here is that video if anyone is interested.

 

Here in Canada the limit is 3500 lbs without trailer brakes. Even if you have a V6 with towing package but no brake controller... still 3500 lbs.

 

It's engine. It would fail the incline start stop test. Brakes are the same across all models. Also lacking the extra cooling and making a small engine work harder is a bad combo.
But if you're only going around the corner basically you shouldn't have an issue. Would be nice if you have 4lo though if your launch ramp is fairly steep.

 

Not all trailers have electric brakes. Many have surge brakes and thus don't need a controller.

 

MTO here doesn't accept surge brakes above 3500 lbs (tandum axle trailers)

 

It’s essentially the same truck as the V6 minus the motor and transmission. As you already wrote you can add all the other tow package stuff. The remaining limitation I could think of would be maintaining freeway speeds when towing heavy loads in the mountains with a 4banger because you WILL be slow.
However, stopping a load is more critical and remember that the tests were done on a stock 4banger which did not have trailer brakes so hence the 3,500 limit. Personally I would want trailer brakes at 2,000lbs and beyond

 

That’s total BS then. In Europe surge brakes is all there is and they tow RVs with station wagons all the time

 

quick read shows surge brakes are good for 2800kg (6100lbs) up there.

 

It’s really unusual to find a boat trailer with electric brakes.

 

It's engine directly because of the incline test but it's also indirectly due to under-powered towing with an automatic transmission means that the transmission is spending a lot of time out of lockup and that means torque converter slippage. That generates a tremendous amount of heat that will cook the transmission.

So on flat ground, you wouldn't be legal in the case of an accident or an over-zealous cop but it probably would be fine towing quite a bit more - especially if you have the tow package hitch and cooler.

 

edit: leaving it up but yeah, missed the keyword.

Not when combined trailer and boat are in excess of 3,500 lbs. Every state in the country requires brakes at that point. When I was wrenching I did a lot of trailer brakes and most anything over 1.5k had brakes on at least one axle.

 

Hydraulic surge brakes. Not electric.

 

oops... missed the keyword "electric"

 

I hate hydraulic surge brakes. I have towed boats a lot. No longer do. Out last trailer was 15,000 lbs rated. 6 individual brake drums with a surge controller. Super maintenance intensive, particularly with salt water use. I see that nowadays there are electric/hydraulic controllers which would satisfy the Ontario regulation. IMO it’s a good idea.

 

Thanks for the responses. 99% of towing would be flat road with 25 mph speed limit, mile or less to ramp. that makes me feel better. The other boats we had came with surge brakes so I am familar with those.

 

I’m ‘that dude’ who did that thing you’re not supposed to do. I had a 1992 Toyota pickup 4x4 22GRE (or was it RE?) in a manual. Twice a year I’d help my buddies tow their heavy sailboats to the coliseum for the boat shows. 4-8k lb keels. Plus trailer and boat. Tongue weights weren’t terrible. I just put it in 4 low and stayed on the access road at 40 or below. They’d always laugh at me coming in with my tiny pickup, but I always put it on the dime where they told me to.