What is the largest tire I can fit with no lift?

[LEX]

They're most likely doing it for the looks.

Most folks like to stick with 16s because they have more sidewall, they have a wider selection and they're easier to find.

 

[Hayes]

I just made the switch from 18" wheels and 275/70R18 to 16" wheels and 295/75R16.
I haven't really had the 16"s off road yet, but day to day on-road I notice very little difference. The ride might be a wee bit more squishy on the 295's. Technically the tires are ~0.25" taller than the 275's, but I don't notice this from a seat-of-the pants perspective. Also, the 295's and 16"s are a heavier setup than the 275's and 18"s, but I don't notice this, either.
As I prefer to air down off road, I am confident that I will notice the additional 1" of sidewall I have work with compared to the 275's.

Revisiting this, I've been reading up on a few threads where 100 owners have sprung for the Tundra 18" wheels. Has anyone here run both 285 or 295 75 16s and also run 275 70 18s on the same rig at one time or another? Was there a noticeable difference in on/off road ride quality, ground clearance, mileage, wear etc? I like the idea of grabbing some Tundra wheels off ebay, I just wanted some feedback from 100 owners who have run both setups on the same rig.

 

[AJLFJ80]

I just made the switch from 18" wheels and 275/70R18 to 16" wheels and 295/75R16.
I haven't really had the 16"s off road yet, but day to day on-road I notice very little difference. The ride might be a wee bit more squishy on the 295's. Technically the tires are ~0.25" taller than the 275's, but I don't notice this from a seat-of-the pants perspective. Also, the 295's and 16"s are a heavier setup than the 275's and 18"s, but I don't notice this, either.
As I prefer to air down off road, I am confident that I will notice the additional 1" of sidewall I have work with compared to the 275's.

Fantastic, just the answer I was looking for. I kind of like the taller sidewall look over cooler looking/bigger wheels, so I was leaning toward the 295/16 set up anyway. My main issue was whether the 18" would provide added ground clearance over the 16", which is important in even the most mundane of trailing situations.

 

[Dog]

If the overall diameter of the tire is the same, then the diameter of the wheel should make no difference in ground clearance.

 

[re_guderian]

I just made the switch from 18" wheels and 275/70R18 to 16" wheels and 295/75R16.
I haven't really had the 16"s off road yet, but day to day on-road I notice very little difference. The ride might be a wee bit more squishy on the 295's. Technically the tires are ~0.25" taller than the 275's, but I don't notice this from a seat-of-the pants perspective. Also, the 295's and 16"s are a heavier setup than the 275's and 18"s, but I don't notice this, either.
As I prefer to air down off road, I am confident that I will notice the additional 1" of sidewall I have work with compared to the 275's.

Are you sure about the weight? From my experience, the same overall diameter tire is heavier with the 18" wheel setup. The 18" tires are heavier due to the larger bead section, which is thick and heavy compared to the relatively light sidewall section on the 16's. I just pulled my 285/65/18 Nitto TG's off and swapped with 295/75/16's. Dang, those 18's are heavy...

I've run 295/75/16's for years with small lifts. Only the slightest of rubbing in the back wheel well was evident, and it must've been crazy articulation. Just bought two more sets of them for both Cruiser today.

 

[re_guderian]

Are you sure about the weight? From my experience, the same overall diameter tire is heavier with the 18" wheel setup. The 18" tires are heavier due to the larger bead section, which is thick and heavy compared to the relatively light sidewall section on the 16's. I just pulled my 285/65/18 Nitto TG's off and swapped with 295/75/16's. Dang, those 18's are heavy...

I've run 295/75/16's for years with small lifts. Only the slightest of rubbing in the back wheel well was evident, and it must've been crazy articulation. Just bought two more sets of them for both Cruiser today.

Apparently, I'm a finely-tuned, weight-sensing, wuss...

According to these specs for Nitto Terra Grapplers, the 275/70/18 combo is ~1 lb heavier than the 295/75/16... Specs seem to show these are equivalent diameters.

275/70/18 = 27+55 = 82 lbs
295/75/16 = 24 + 57 = 81 lbs D rated

For Toyo Open Country AT II's - different story, but the 295's are the "XT" version and E rated, and are also rated for >300 lbs more load per tire. Toyo specs show the 295/16 as .2" larger diameter.

275/70/18 = 27+53 = 80 lbs
295/75/16 = 24 + 64 = 88 lbs


Wheel weights here: https://forum.ih8mud.com/threads/oem-wheel-weights.463603/

Nitto Tire weights here (not official Nitto source): http://www.carid.com/images/nitto/info/dimensions/nitto-terra-grappler.html

So I guess the weight difference depends on what you are comparing, and is not a given.

 

[Hayes]

Good comparison and good point. The XT AT2s are definitely beefy, due to an extra sidewall ply and a bit more rubber on the tread face.

Apparently, I'm a finely-tuned, weight-sensing, wuss...

According to these specs for Nitto Terra Grapplers, the 275/70/18 combo is ~1 lb heavier than the 295/75/16... Specs seem to show these are equivalent diameters.

275/70/18 = 27+55 = 82 lbs
295/75/16 = 24 + 57 = 81 lbs D rated

For Toyo Open Country AT II's - different story, but the 295's are the "XT" version and E rated, and are also rated for >300 lbs more load per tire. Toyo specs show the 295/16 as .2" larger diameter.

275/70/18 = 27+53 = 80 lbs
295/75/16 = 24 + 64 = 88 lbs


Wheel weights here: https://forum.ih8mud.com/threads/oem-wheel-weights.463603/

Nitto Tire weights here (not official Nitto source): http://www.carid.com/images/nitto/info/dimensions/nitto-terra-grappler.html

So I guess the weight difference depends on what you are comparing, and is not a given.

 

[AJLFJ80]

Good info here, interesting to see the weight fluctuation between the tire types. I wonder how much of an effect 8 lbs/tire would have on rotational inertia?

 

[Hayes]

Good info here, interesting to see the weight fluctuation between the tire types. I wonder how much of an effect 8 lbs/tire would have on rotational inertia?

(mass)(radius)^2

 

[Hayes]

(mass)(radius)^2

Or the way I think about it:
Tire size has a much bigger effect than tire weight.

Roughly speaking, a 3% increase in tire size has about the same effect on rotational inertia as a 10% increase in tire mass. This assumes that the additional mass is all located at the full outside radius--which is obviously incorrect--so the effect of added tire mass is probably a wee bit overstated in this comparison.

 

[re_guderian]

Or the way I think about it:
Tire size has a much bigger effect than tire weight.

I'm a physics hack, so take this FWIW, but I don't think it's that simple? Tires don't have a constant density as you go from bead to tread. Maybe it's close enough?

 

[AJLFJ80]

I mean that would make sense, no one with an 80 is regearing just because they have beefier, heavier tires. Of course increasing your tire size also means an increase in tire weight, so the added unsprung weight is really twofold.

 

[Hayes]

I'm a physics hack, so take this FWIW, but I don't think it's that simple? Tires don't have a constant density as you go from bead to tread. Maybe it's close enough?

Was just editing my post to recognize the simplification.
The relationship is true, but the story in a wheel and tire is more complicated. Regardless, adding mass (weight) does increase the rotational inertia, but adding radius (tire diameter) adds much more, relatively speaking.

 

[Dog]

Nerds...

 

[Chris Sandstorm FJ]

I just picked up a set of 295/75/16 Toyo AT IIs.

I am lifted.

Great tires and really nice profile, I like them so much better than 285s and the 255s I was running. Super quiet...

 

[Ole Colony]

Does rim height have any effect on tire height when aired down comparing a 295/75/16 (33.4) to a 275/70/18 (33.2). I am thinking with less side wall the 18" have more height.

 

[AJLFJ80]

Just FYI, I got a set of Terra Grapplers put on Friday--295/75/16. Even though the owner of the tire shop looked at me sideways and gave me a bit of guff(good-natured, I'm a regular customer at his shop)when he saw what vehicle the tires were going on, they fit easily, no rub, and they look fantastic. Not for nothing, the TGs were the LEAST EXPENSIVE tire they had available for that size; $870 out the door.

 

[LEX]

Just FYI, I got a set of Terra Grapplers put on Friday--295/75/16. Even though the owner of the tire shop looked at me sideways and gave me a bit of guff(good-natured, I'm a regular customer at his shop)when he saw what vehicle the tires were going on, they fit easily, no rub, and they look fantastic. Not for nothing, the TGs were the LEAST EXPENSIVE tire they had available for that size; $870 out the door.

So what are your immediate thoughts coming from 275/70s?

 

[slingblade]

Personally when i went from stock size (265) michelin ltx tires to nitto trail grapplers in 285 75 16, i lost almost 3 mpg, ride was noticibly compromised, and my stock LC became mud and snow BEAST. now that i got that out of my system i am going to new tires next week and they are bfg ta ko, i am hoping for the best compromise. A more supple ride with some off road capability and hopefully get back to 14 mpg avg.

 

[AJLFJ80]

So what are your immediate thoughts coming from 275/70s?

The ride is definitely firmer, but I prefer that, and the on-road handling seems to be better too. The only negative is that when tracking in a straight line, the front end is noticeably twitchier, but that may be due to the fact that right before i got the tires put on, I cranked the torsion bars up 4 turns on each side too. I will be getting an alignment Friday, so hopefully that will help with the twitchiness in the front end. Haven't had a chance to use it off-road yet, unless you consider moping along the outside rows of the vineyard off-road (I don't).