1st Gen Toyota Tundra Tire Size - Feedback

[super doody]

Hi All,

I'm currently running P285/70R17 (32.8'') (Toyo Open Country AT2) on a 2006 Tundra Double Cab with a fully optioned Hawk (1440 lbs dry). I would like to replace my existing tires with E rated tires for some upcoming trips.

My initial though was to replace with E rated tires of the same size but for overall efficiency and power, I'm thinking about down sizing to 265/70R17 (31.5'') on an already somewhat underpowered, heavy double cab truck.

The difference is between 265/70R17 and 285/70R17 is 3.9% in diameter and 7 lbs of rotation mass per tire.

I due intend to take more trips offroad but most of my driving will still be on pavement. Downsizing would be more expensive as I have to replace my spare tire as well.

I can't seem to make up my mind so your feedback is appreciated .

For 1st gen Tundra (especially those with Double Cabs) pop up camper owners:

1 What size tire do you run?
2. How are they performing?


Thanks,

Jim

 

[cerve137]

A little off topic, but I when I got my first gen 6 years ago, I wanted a tough look so I went with 285 60 18's on heavy 18x8 granite alloy rims. They looked great on the truck, always got compliments, but the truck became even more of a dog. When my FWC came into the picture I found some late model Tacoma steelies and went with 265 70 16 Michelin LTX. Power and fuel economy were restored and the truck just feels a whole bunch happier. The most offroad my truck gets with the camper on is just logging roads or gravel grade. Best of luck with your decision.

 

[Lighthawk]

My 06 AC Tundra came with 18" aluminum wheels when I bought it over five years ago. I put on a set of BFG 265/65 18" and got 30k usage with good results. I've since replaced them with another set of same. We do take some rough trails, although pavement will always be the vast majority of use.

I've always felt the 4.7L engine was up to the task giving me plenty of power. It's the brakes and gas mileage that I feel need improvement. We also carry a Hawk that is pretty well loaded.

Back to your concern: Do you think the 3% downsizing will translate into a better effective gear ratio?

 

[iowahiker]

I do not know what rear end ratio you have but for reference: my dealer said I would notice the difference between a 3.73 rear end and a 3.55 and so recommended I get the 3.73 rear end since I carry the camper full time. A 3% larger rear tire circumference would convert a 3.73 rear end to a 3.62 (.97 x 3.73). Given your smaller V-8 it would appear to make a difference. The rear end ratio makes the most difference climbing mountains or driving into a head wind or pulling a trailer, all at high speed, since these are the highest torque situations for us. The more time you spend in lower gears outside these high torque situations the less you will notice 3.73 versus 3.62 or in your case what your rear end ratio is.

Also, dividing your tire diameters of 31.5 inches by 32.8 produces a change of 4%. Redoing the calculation:

3.73 x 31.5 / 32.8 = 3.58 equivalent rear end ratio which is getting close to an entire rear end diff swap in the weaker direction in the Ford lineup.

 

[super doody]

My 06 AC Tundra came with 18" aluminum wheels when I bought it over five years ago. I put on a set of BFG 265/65 18" and got 30k usage with good results. I've since replaced them with another set of same. We do take some rough trails, although pavement will always be the vast majority of use.

I've always felt the 4.7L engine was up to the task giving me plenty of power. It's the brakes and gas mileage that I feel need improvement. We also carry a Hawk that is pretty well loaded.

Back to your concern: Do you think the 3% downsizing will translate into a better effective gear ratio?

I haven't done the math but I think it will. On my Tacoma, I went from 265/70 to 265/75 and noticed a difference in mpg.

 

[super doody]

I do not know what rear end ratio you have but for reference: my dealer said I would notice the difference between a 3.73 rear end and a 3.55 and so recommended I get the 3.73 rear end since I carry the camper full time. A 3% larger rear tire circumference would convert a 3.73 rear end to a 3.62 (.97 x 3.73). Given your smaller V-8 it would appear to make a difference. The rear end ratio makes the most difference climbing mountains or driving into a head wind or pulling a trailer, all at high speed, since these are the highest torque situations for us. The more time you spend in lower gears outside these high torque situations the less you will notice 3.73 versus 3.62 or in your case what your rear end ratio is.

Also, dividing your tire diameters of 31.5 inches by 32.8 produces a change of 4%. Redoing the calculation:

3.73 x 31.5 / 32.8 = 3.58 equivalent rear end ratio which is getting close to an entire rear end diff swap in the weaker direction in the Ford lineup.

Thanks for double check my mental math. Its actually 3.9%. I'll update my OG post.

 

[Casa Escarlata Robles Too]

I have a 2002 Tundra AC TRD 4X4 Limited.
When I bought the truck 5 years ago it came with "new" Goodyear 265 75 R16 C rated M+S Wrangler tires.
I have put 25K miles on the tires,have 11/32 tread left across the set. My mileage runs about 15.5 to 16.5 MPG.
The Bobcat camper is on full time.
Most of my driving is hwy with some off road.
I am happy with the tires and will replace with the same.
As for a spare it's same size and used.
I am happy with the tires and they give a nice smooth quiet ride.
They get rotated every service and have #40 front #45 rear.
Frank

 

[super doody]

All,

I still haven't made a decision yet about my tire size. I think majority of owners with gen 1 tundras go with 265/75 because they have stock front suspension. I have sway away coil overs with a very mild 1.5'' lift. I'm still leaning towards 285/70 for off road ability. Both Sunman and Wake the Dead Diaries have coilovers and run 285/70. I did find a local place with good prices on cooper discoverer at3 tires.

Mileage wise, it will still be horrible even if I went with 265/75.

 

[JHanson]

Well done for even considering fighting the dominant paradigm of ever-larger tires. I think the switch to a slightly smaller diameter would be beneficial, and I don't believe you'd notice any difference in off-pavement ability with a .6" loss of ground clearance or the slightly narrower footprint. You'd gain a bit of acceleration, and the lighter weight would help offset the stiffer carcass of the E-rated tire. A lighter tire with less rotational mass is easier on the suspension and easier on the brakes.