Larger tires affect on towing?

Hey all, we are going to be buying a new boat here soon, and while I don't think it will be an issue, I just want to get some clarification on towing. Our stock gearing is 4.30, the stock tire size is 32". Stock towing is 9,000 pounds.

Increasing to the 295/70-18 size tire, size increases to 34.3, this effectively reduces the stock gear to 4.02.

Question, how will the lower gear affect towing? will it decrease it substantially? just make it harder to tow? etc., I'm considering buying a cheap set of rims and stock size tires to use when towing, but if it's not necessarily, id hate wasting the money on it. what are your guys thoughts?

 

I basically have the same tire size - but in a 20" and the only thing it will affect is the MPG. You won't notice a loss of power. I'm pulling about 10K when my trailer is fully loaded. I set the cruise at 62 (really 66) and enjoy the drive.

 

You’ll be fine

 

You use cruise control while towing?

 

I do all the time.

 

I would t recommend that. Owners manual even says not to use cruise while towing. Lol if it works for you go for it.

 

I can understand it not being recommended for your normal person who is ignorant and doesn't pay attention to their truck making noises or feeling things. It's not gonna hurt it being on flat ground with cruise control on, I know when the truck is happy and when I need to take over control. Nothing wrong with it chugging along not shifting and letting my leg rest.

 

just curious what MPG do you get normally not towing and when towing with your 295/70/18?

 

Not towing is usually 13mpg, that's with the supercharger and it was maybe 1mpg higher before the blower. That's mixed city/highway. This past weekend I drove 1000 miles round trip to Colorado and back, and actually averaged around 15mpg for the whole trip, and that was usually speeding by 5mph and with 80mph speed limit in Utah

Towing varies a ton, I have a UTV and 2500lb 18ft flat bed (4000lbs total) and usually get 11-12mpg. When I tow heavier stuff (cars, my buggy, etc.) it plummets pretty fast to like 8mpg. I got the UTV after the supercharger, but before the supercharger I still got around 8mpg towing heavier stuff and just had to slow down more on hills. No denying I drive fast (the blower helps a lot) so if you're more conservative you'll probably get quite a bit higher mpg.

All stock besides the supercharger and a 3" lift. Stock gears, stock wheels, etc. Just some ~35"x11" tires.

 

I have the same size Michelin tires, 295/70/18 E rated ties and what I found is it is really dependent on how fast you want to go. IIRC a 295/70/18 tire will be +3.5 mph over what your speedometer says. So 70 mph is really 73.5 mph.

That being said, I have had to slow down some with the bigger tires and towing - otherwise my mileage just blows. If I have a headwind, and an open 14' trailer (2 atvs, 2 dirt bikes) I will routinely get 11 mpg at 73.5 mph. Add a 20 mph headwind (aka traveling across North Dakota) with smallish hills and I go sub 10 mpg.

Not towing or just a motorcycle trailer w/295 tires gives me around 12.5-14.0 depending on any hills and speed.

With the bigger tires and the 14' open trailer and a head wind, there were times the truck never went into 6th gear.

So now I am contemplating either:

1. Taking the mileage hit and dealing with it, or;
2. ReGearing the truck, or;
3. Moving into a Duramax diesel and spending wayyyy too much money

 

Think of how many gallons of gas you can buy with the extra money you would spend on that Duramax? Better yet calc the difference in MPG and then see how long it will take to break even.

 

Exactly why I don't already have one. I got a smok'in trade in offer on the Tundra and had test drove 3 of them (Chevy/GMC 2018, 2019, 2020). So yah...am doing that mental check. But DaHam.......would be nice to start s duramax build project, or get a new one with the 10 speed Allison. All drool worthy.....but I don't have endless pockets.

 

That matches about what I get. I got about 8 mpg towing 6600 lbs recently.

 

My question is our tundra calls for 49 psi but we dropped it down to 45 psi for comfort will this all affect towing? Does it matter? Nitto ridge grapplers