How big is big enough? - Tire sizes

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Speric

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I know the answer is "depends", and there are a lot of factors in deciding how big to go. Looking at rigs online, seems like a lot of folks like to run 35s, 37s and even 40s, which often requires adding a lift and re-hearing, etc. But then you look at other vehicles where going up to a 31 or 33s is plenty. However, it seems there is this push to going bigger.

What made you decide to increase the size of your tire? what size did you go to? and did it really expand where you could go?

Or, did you keep stock tire sizes and got something with better grip to expand where you could go? and why did you stay on stock sizes? Do you feel that's big enough?

To answer my own question:
I have a stock 98 Tacoma with 31s. I've had it since 2000. I've been able to do a some off-roading over the years, and have rarely felt the need get bigger tires, and then have to do all the additional mods to make them fit and for the truck to run well.
 
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I have 31's stock and plan on 33's when these get thin. My truck is geared high with 3.42 stock and I went with 4.10's major improvement in drivability, actually picked up mpg in town, lost on the freeway. When you get up to 35" and above you really start adding stress to the drive train, another reason I'm not going over 33".
 
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When it came time for me to buy new tires I did consider bigger tires. Larger tires come with a large price tag though. And I wanted a quality tire at an acceptable price. 1900 bucks for all terrain tires was a nope. I kept the stock size but decided to go for a more aggressive tire. And oddly enough was about 700 dollars cheaper than the ko2s I had quoted. I also didn't want to stress the drivetrain with heavier tires, or my whopping 11 mpg lol.
 

jplemons

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I have 31's stock and plan on 33's when these get thin. My truck is geared high with 3.42 stock and I went with 4.10's major improvement in drivability, actually picked up mpg in town, lost on the freeway. When you get up to 35" and above you really start adding stress to the drive train, another reason I'm not going over 33".
Sounds like a ZR2. Wait, it is. Lol. I’m waiting to see what AEVs big announcement is and then possibly move up from the stock to 33s. I think that’s all I’ll need. I’ll wait for the warranty to expire before I regear.
 
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Mike W

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I'm running 265/65R18 which is 31.5" and about as large as I can go without more involved mods. Because I am on air suspension I don't want to have issues if worst case I am on the bump stops (usually its a computer fault or sensor which I can easily bypass with my little Gap IID tool, or even manually air them up, bags are extremely tough and don't really burst)

I'm sure the choice for many people has a lot to do with clearance, or gearing, looks, etc Lot's of folks have a lot more freedom for size. My little 31" tires seem tiny compared to a 37"-40" tire, but lugging that around and doing thousands of highway miles doesn't seem very appealing to me. The unsprung weight really does have a big impact on drive-ability. (But then again, my rig is crazy heavy, so I can't proclaim to be great on that front.)

I just today got new KO2's put on. I had Goodyear Silent amour in the same size since 2013. They wore like iron, but didn't have the E-load rating or 10 ply construction or the awesome sidewall protection like these do. I finally just had to bail on the goodyears ... I wanted new dang tires. I love the look and I hope to put them to good use and see what they can do. I paid for the extra replacement warranty that is good until 2/32" tread and good for 10 years... lol... hope to get my money worth out of that!

98619
 

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I've got 35x12.5s on my taco and have actually decided to go down to something that'll be approximately 34x11. After replacing hub bearings after 12k miles, losing too much of my turning radius, and typical rubbing issues I'm hoping for improvements.20190322_124316.jpg
 

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Sounds like a ZR2. Wait, it is. Lol. I’m waiting to see what AEVs big announcement is and then possibly move up from the stock to 33s. I think that’s all I’ll need. I’ll wait for the warranty to expire before I regear.
Did you see the new fender flares from AEV, reported to allow 33's without a lift and 35's with minor lift. It does involve cutting the sheet metal. There are more and more peeps going to "pizza cutter" a taller narrow tire, like a 255/75/17, helps with rubbing frame and sway bar.
Rocksylvania made a great point, there are down sides to oversize tires. The midsize truck seems to me to be happy around 33", 35" and you start wearing out parts and have part failure.
 
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CSG

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I run close to stock tires on my LX470 (265/75/16). I don't need or want larger. The 265/75 are slightly taller and narrower than the stock 275/70 tires. It was mostly a cost issue as 265/75 tires are more available and less expensive.
 
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Bigger tires are absolutely technically better over rough terrain, and will generally create a more somfortable ride, but we must balance the perceived value of that benefits with all the very-real downsides of going larger. I had ~32" ATs on my wife's 4Runner TRD Pro, and went back down to 31" MTs that actually perform better in pretty much every area we use it.

Probably 40% of my motivation for larger tires is aesthetics, while about 60% is to increase the sidewall.

Factory tires for the 2019 Rav4 are 28.5-29.3", depending on trim. I just went from 19" wheels down to 16" wheels, and increased the tires to 30.1", all so I could get more sidewall, and somewhat for the aesthetics.
 
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Steve in Roanoke VA

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I know the answer is "depends", and there are a lot of factors in deciding how big to go. Looking at rigs online, seems like a lot of folks like to run 35s, 37s and even 40s, which often requires adding a lift and re-hearing, etc. But then you look at other vehicles where going up to a 31 or 33s is plenty. However, it seems there is this push to going bigger.

What made you decide to increase the size of your tire? what size did you go to? and did it really expand where you could go?

Or, did you keep stock tire sizes and got something with better grip to expand where you could go? and why did you stay on stock sizes? Do you feel that's big enough?

To answer my own question:
I have a stock 98 Tacoma with 31s. I've had it since 2000. I've been able to do a some off-roading over the years, and have rarely felt the need get bigger tires, and then have to do all the additional mods to make them fit and for the truck to run well.
My Taco is a 99, drivetrain is stock. Have 31's right now, and like you have not really needed anything bigger. I have not done any rock crawling, stick to forest roads & milder trails. I do have sagging leaf springs & Taco lean, so a suspension upgrade is definitely in my future. I plan on doing a MILD lift when uprading, 1.5 - 2.5 inches, looking seriously at Old Man Emu. That MAY make me change my mind on bigger (taller) tires, but at the most I'm thinking 33's. There is also a shrinking market for 31's, so going up to a 16 or 17 inch steelie may be more economical tire-wise in the future. My educated guess is that the closer to stock I can stay, the longer my vehicle will last.
 
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Todd & Meg

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As tires get bigger cost goes up and reliability goes down. If you are a rock crawler, mudder, or mall crawler go as big as you can. I think for overlanding you want to lessen the chance on breakdowns. Avoiding bigger than needed tires does that. For a Jeep I think 35’s and smaller are better. I’ll probably move up to a 34” on our next set, or stay with the 33’s we have now.

Another thing we notice we are putting on more highway miles to get to places we haven’t been to before. I wouldn’t not want to go somewhere because I’m worried about putting ware on our tires.

Todd
 
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Same dilemma, getting Icon stage 6 suspension on 2018 Tundra and was told by one offroad company to run 33" K02s and another to run 35" KO2s and most said to go with 35" and some said 33". Do I get the filet or the ribeye? Wish it was that easy. Unfortunately I am new to the whole 4W drive thing. Tundra is much bigger so hopefully going with 35" won't be a mistake cause that is what I chose after reading so much.
 

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I run 35's on my Cruiser with 4:10's. I lost a bit of torque and some mileage. The axles and bearings have no issue supporting this so I'm ok there. I keep saying I'm going to drop down to 33"s when these are done but, it looks great with 35's. My new Tacoma will get a better tire close to stock size.

Some things to consider when buying bigger tires and rims.
1. Unsprung weight. This is everything not supported by your springs. Tires, rim's, brakes, hubs... Take this weight and turn it into kinetic energy. Your shock and springs turn this into heat while controlling it. Stock suspension isn't very happy about making this any bigger. Most vehicle suspensions are not even designed to handle the extra energy from just dirt roads and stock tire/rim's.

2. Brake systems. Your brake system turns kinetic energy (weight/speed forward) into heat, using friction. Your brake system has a max heat rating. Push aside for a second all the weight you added with accessories. Draw a circle on a piece of paper 3" across. In the center draw one 1/2 inch across. Put a dot in the center of all this. Draw a line straight down from the center to the outer ring. The outer ring is your tire, the inner your caliper/rotor, the line is a lever. Imagine trying to hold the lever still at the smaller ring while someone is turning it at the outer. Now increase the outer ring diameter. You just increased the leverage against the rotor, that's taller tires. Now turn this into extra heat.
The taller the tires, the harder your brake system has to work to stop you. We cant buy cheap brakes.

3. Bearings. This one is simple. obviously more weight is harder on them but, your stock rims are set to keep the vehicle weight centered on them. Using rim's that move the tire out to gain clearance, moves the weight outward and instead of being centered, actually increases the force due to leverage.

4. Ball joints. Way more stress. These take a pounding. The more traction you have, the more twisting action. Very few companies make upgrades for these without major suspension work. My TJ went through its first set in 18k miles. I did drive it hard with 37's.

Most vehicles are fine as long as you stay within a few sizes bigger than stock. Much bigger than that you should do upgrades on things.

Positive's of bigger tires/rims.
1. look cool as hell
2. clearance.
3. flotation/traction
4. legitimate reason to upgrade suspension.
5. look cool as hell
 
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Had 35s (315s) and they were horrible for the long tours we take and the steering components were wearing out every 25k miles or so. I’m pleased with 33s (285s) as they seem to mate perfectly with the OME heavy suspension and we can crack 14 mpg on a good day. If you are just going 4 wheeling then the sky is the limit, but be prepared to open your wallet. If you are overlanding, you need a tire size that is Practical , Dependable & available. Any tire store in North America can get a 285-75-16 within 24 hours if it’s not on the shelf already. I wouldn’t want to be in the boonies of Newfoundland trying to find a 35x12.50 x18.. good luck. KISS
 

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My Taco is a 99, drivetrain is stock. Have 31's right now, and like you have not really needed anything bigger. I have not done any rock crawling, stick to forest roads & milder trails. I do have sagging leaf springs & Taco lean, so a suspension upgrade is definitely in my future. I plan on doing a MILD lift when uprading, 1.5 - 2.5 inches, looking seriously at Old Man Emu. That MAY make me change my mind on bigger (taller) tires, but at the most I'm thinking 33's. There is also a shrinking market for 31's, so going up to a 16 or 17 inch steelie may be more economical tire-wise in the future. My educated guess is that the closer to stock I can stay, the longer my vehicle will last.
My suspension is getting a bit long in the tooth too. They're squeaky, i think I get that lean, i really just bounce around on washboards, etc. That said, I might also be getting a new truck within the next year. I think I'm ready for just something new.
 

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What a few episodes on 4wd Action. It's fun watching Graham run the same obstacles in his 31" tired Isuzu DMax as Shaun does in his 35" tired Land Cruiser. It's instructive as well. There are many times the DMax bottoms out and has to winch where the bigger tired trucks make it look easy. On the otherhand, there are times where the DMax's low center of gravity makes it easy to climb steep off-camber terrain where the big lifted rigs struggle or roll.

Mod for how you use your rig. More isn't always better.

Skip to time 1.07:40 or enjoy the whole episode. :)
 

JCWages

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I missread your intent for the thread. :) So here is my answer.

My truck comes stock with 30.5" tires. It also suffers from low ground clearance (8.3" or so) and a fairly long wheelbase (128.3"). So larger diameter tires and a lift to accomodate them were my first order of business to be able to more safely and comfortably navigate the rocky trails in my region.

I started with 32" (255/75/17) Geolandar AT G015 mild-terrains and they worked very well but are too fragile for where I planned on taking the truck. I also found I needed a bit more clearance, especially when aired down. So I stepped up to a 32.8" Wildpeak AT3W (P285/70/17) which provided loads more traction and a bit more height and lots more confidence in terms of tire toughness. With that came a noticeable loss of braking power and the need to recalibrate my shift points as well as a little loss in fuel economy. These had a vibration I couldn't balance out so after 8k miles the tire shop replaced them with LT285s E-load which are true 33.1" and 9lbs heavier each. Now I really feel the loss of braking power and feel like a re-gear would be very nice although not 100% neccessary. My fuel economy at high speeds while fully loaded with camping gear tanked. I used to average 19+ in such conditions and on a recent trip I was getting high 13s to mid 14s. It appears I crossed a line with the new tires and now the truck can't stay in my high gears (8spd trans) when driving over 70mph loaded down.

Soooo for my particular truck and usage I hit a wall with the 33s that will require loads more work and money to accomodate a larger (heavier) tire and the increase in capability is simply not worth it to me. As such I decided to take my lightly used 32" Geolandars off the market, mount them up to my factory wheels and use them for long family trips where the much heavier 33s make me sad. The loss of 25lbs per corner really helps driveability and fuel economy on long trips where the big tires are absolutely not needed and I still have decent off-road capability with the Geolandars.

If my wheels were narrower than 9" I would consider a 255/80/17 as my next tire choice to shave off some weight and better aerodynamics but I worry about popping the bead. #firstworldproblems
 

Pathfinder I

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I missread your intent for the thread. :) So here is my answer.

My truck comes stock with 30.5" tires. It also suffers from low ground clearance (8.3" or so) and a fairly long wheelbase (128.3"). So larger diameter tires and a lift to accomodate them were my first order of business to be able to more safely and comfortably navigate the rocky trails in my region.

I started with 32" (255/75/17) Geolandar AT G015 mild-terrains and they worked very well but are too fragile for where I planned on taking the truck. I also found I needed a bit more clearance, especially when aired down. So I stepped up to a 32.8" Wildpeak AT3W (P285/70/17) which provided loads more traction and a bit more height and lots more confidence in terms of tire toughness. With that came a noticeable loss of braking power and the need to recalibrate my shift points as well as a little loss in fuel economy. These had a vibration I couldn't balance out so after 8k miles the tire shop replaced them with LT285s E-load which are true 33.1" and 9lbs heavier each. Now I really feel the loss of braking power and feel like a re-gear would be very nice although not 100% neccessary. My fuel economy at high speeds while fully loaded with camping gear tanked. I used to average 19+ in such conditions and on a recent trip I was getting high 13s to mid 14s. It appears I crossed a line with the new tires and now the truck can't stay in my high gears (8spd trans) when driving over 70mph loaded down.

Soooo for my particular truck and usage I hit a wall with the 33s that will require loads more work and money to accomodate a larger (heavier) tire and the increase in capability is simply not worth it to me. As such I decided to take my lightly used 32" Geolandars off the market, mount them up to my factory wheels and use them for long family trips where the much heavier 33s make me sad. The loss of 25lbs per corner really helps driveability and fuel economy on long trips where the big tires are absolutely not needed and I still have decent off-road capability with the Geolandars.

If my wheels were narrower than 9" I would consider a 255/80/17 as my next tire choice to shave off some weight and better aerodynamics but I worry about popping the bead. #firstworldproblems
Tire weight is my concern also. I find several tires that would fill my needs but they double the weight in some cases. I have P rated Duratracs, these are fairly light weight, a little lacking in sidewall strength.
I'm leaning toward the 255/75 or 255/80. I like the falken wildpeak at3w in 255 but it's only avaliable as a mud tire, very aggressive and probably very noisy. I can go up one size in the Duratrac (265/70) gain 1" and 18lbs.

If you ever get a chance to drive a Colorado with the trifecta tune you need to try it. It improved my mileage, trans shift points, and I have extra power at the flip of a switch to enable Sport mode. The 4.10's with the Trifecta made my 3.6 V6 a whole different truck.
 

jplemons

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Did you see the new fender flares from AEV, reported to allow 33's without a lift and 35's with minor lift. It does involve cutting the sheet metal. There are more and more peeps going to "pizza cutter" a taller narrow tire, like a 255/75/17, helps with rubbing frame and sway bar.
Rocksylvania made a great point, there are down sides to oversize tires. The midsize truck seems to me to be happy around 33", 35" and you start wearing out parts and have part failure.
That’s exactly what I’ve been looking into. I don’t think I have a need for 35s. Plus, to make it right, I’d need to regear. At 33s, I could get away with the GM front lift kit. If I add a winch and bumper, maybe use the Peak suspension coils to handle the extra weight.

But the 255 option has me intrigued and sounds like a great option.
 

JCWages

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Tire weight is my concern also. I find several tires that would fill my needs but they double the weight in some cases. I have P rated Duratracs, these are fairly light weight, a little lacking in sidewall strength.
I'm leaning toward the 255/75 or 255/80. I like the falken wildpeak at3w in 255 but it's only avaliable as a mud tire, very aggressive and probably very noisy. I can go up one size in the Duratrac (265/70) gain 1" and 18lbs.

If you ever get a chance to drive a Colorado with the trifecta tune you need to try it. It improved my mileage, trans shift points, and I have extra power at the flip of a switch to enable Sport mode. The 4.10's with the Trifecta made my 3.6 V6 a whole different truck.
The Wildpeak AT3W is offered in a 255/80/17 *evil grin*

That's what I would try out if I had an 8" wheel. A true 33" and only 52lbs in an E-load. I'm also finding the Es don't ride as terrible as I expected. At 35psi they feel slightly firmer than the P-metrics but totally liveable so I wouldn't be afraid to try them out. Especially for off-road use like we subject tires to.

Eventually I'll need a tune but I'll wait until I do gears. My buddy (Synergy Motorsports) has been tuning late model GM muscle cars/trucks since 1998 so I'll have him do it so we can verify it on his dyno and on the street. It's easier to get it right the first time vs. mail order. I'm happy to hear the tune really helped your situation. Once you go way outside of GMs intended design things start to fall apart without proper tuning. :)