Increased tire size/weight and towing

I haven't had much response in the "wheels & tires" section, so I figured I'd post up in here since it relates to towing as well.

I have a 2015 TRD Sport 4x4 auto and tow a 4,000lb dry weight travel trailer about 1,700 miles a year from Florida to the North Georgia mountains. I have a WDH and brake controller, and feel fairly comfortable towing it with the Tacoma.

My question is I'm upgrading the original tires to BF Goodrich KO2s (C load rating) in the next sidewall size up 265/70/17 on some new SEMA PRO wheels.

Does anyone have any noticeable experience of loss of power/torque with this setup while towing? I know with the additional weight of the all terrains and the slightly larger diameter it will decrease power, but is it really worth splitting hairs over? Am I simply worrying too much?

Thanks for your input and advice guys/gals!

 

Not apples and apples but I'm on my second set of 265x75 R16's KO2's on my 2012 TRD OR. Just got back to NC from five weeks in southern Utah. Camper is a 19' Scamp (hybrid gooseneck/fiver/ball) weighing in around 3,500 lbs. We were up to 10.5k Ft around Cedar Breaks and it pulled fine. Avg mpg for 6k miles was around 13.5. Would definitely go this way again.

 

Compare the current tire size to the new in the Tire Calculator. You can see the RPM / effective gear change it creates and decide from that.

 

Ive towed on D load 33's and it was not that bad compared to the stock tires. But that was a different vehicle. The D load is nice because they are very stable when towing, can pump them up to 80psi if needed. You should be fine on such a small tire and C load.

 

I am running 270x75x17s, don't tow what you do, but I added air bags and tow my Jeep from CA to UT at 80 to 85 with no problems.

 

You guys are awesome, thanks for the quick responses!
I've never messed around with tire sizes on any of my vehicles before so I just wanted some reassurance that I wasn't going to drop 1K on some tires and regret my decision when towing!!!
Thanks ClearwaterBill for the link, I was messing around with that before, but really had no tangible experience to base a ratio change to a "seat of the pants" feel that I might experience.
That coupled with the additional weigh had me questioning my decision.
Looks like I'll be bumping up a size!!
Thanks again!!!

 

I'm currently running C load 265/75/16 duratracs and it tows my 4,500lb dry weight travel trailer fine, even at elevation and in the mountains. 65mph is the sweet spot...at 55mph it hunts around between gears a bit.

I'm planning to go up another size to a 255/85/16 and will likely end up regearing from 3.73 to 4.30.

 

This is exactly what I wanted to know! Sounds like you've got the closest senecio to what I'm trying to gauge.
And yes, 65 is the sweet spot!