Another Tire Thread-MPG/Power loss with LT285/70R18 Only?

I’m currently running LT275/70R18 Goodyear Ultraterrains (55lbs) on stock TRD Pro wheels (18x8). I have slight lift of about 2.5” in from on TRD Pro Fox with Couchbulder shins and about a 2” lift from custom Alcan springs in rear. I am currently getting at best around 15.1 combined MPG. I don’t think I noticed any power/acceleration/shifting loss, but I switched from OEM 275/65R18 (maybe 47lbs?)the day after buying my Tundra. My Speedo also seems exactly correct up to 90mph according to GPS.

Every time I look at my truck from any distance, those 275’s look a little small proportionally to the size/lift of the truck. I am looking at jumping up to a LT285/70R18 Nitto Exo Grappler (64.27lbs) on the same Pro Wheels. Question is, have those running the 285’s noticed MPG loss, Power loss, Shifting issues, Speedo difference?

I don’t want to get into re-gearing or having to use the hypertext to reset Speedo. 1-2 mph difference is livable. I know there are a lot of threads for Tires, I’ve read just about everyone. Most are about 295’s or larger, or the 275’s, and mostly only ask about rubbing (Not my concern). Appreciate input from those on 2.5 Gen Tundras running LT285/70R18’s. Pretty much only tires in that size are Nitro Ridge or Exo Grappler and a few other brand MT’s.

 

I run 275/70s and speedo is more accurate now than with the stock 32s. 285s are a little bigger, heavier so yes you will see an impact in power/mpg. Few in that size, RG being the best IMO. If that is a concern, keep your 275/70- great tire on a tundra- added performance and looks without a huge hit on MPG and power.

You should not have an issue running them. 285/70 fit on a stock SR/Sr5 truck, no lift with stock wheels just fine so they will certainly work on your Pro.

Not much difference between 285 and 275s, so it you are looking for a bigger tire 295/70 or 285/75 wont look too small. Lots of tires in those sizes. And yes, bigger/heavier the tire the more impact to feeling of power and MPG.

 

I had 285/70/18 RG put on my truck when I first bought it new. I have the westcott lift to add. I did not do it yet. After driving it home with the stock size tire and then switching to the 285’s I did notice a little power loss which is normal because of the size and weight of the tires. But after driving it a few days the truck feels fine with the power. I did drive to OBX and Portland MA. Last year on vacation and I was averaging about 16 miles to the gallon. Considering doing 70 to 75 highway. I was planning on 295’s at the time but changed my mind because of power loss and gas. I have new wheels and the lift I have not added yet. But I was still planning on staying with the 285’s. If I would decide to change then I would add the 295’s. I think the 275’s are not much different than the stock size. I noticed a big difference look with the 285’s. Just my opinion. Hope this helps.

 

For tires , 285/70 is slim picking, if weight is a concern, go with 295/70r18 Nitto Terra Grappler 2, it's available in C-load index and only weights 52lbs.

From your profile, you've added some heavy stuff, so why not go with 285/75r18? they are skinny 35s and often run true 35" OD, I've been running them since day one, the power loss is ok, and the speedo difference you kinda get used to it.

For fuel consumption, regear actually helps with it, after regear I'm usually @ 15mpg, now the kicker is when you add supercharger to the mix, last weekend I saw 17mpg while doing 80mph and city traffic, while on 35s.

 

no regear needed, I run 315/70r17 and the power feel adequate enough for me. YMMV

 

I definitely added some heavy stuff. Tuff choices, I’m just feeling the pain at the pump right now. Ha