Jump to content

Tires Tires Tires


jhamelin819
 Share

Recommended Posts

I'd say it depends more on the driving you do. A friend of mine has 30" tires on his 1992 and thinks they are perfect; he uses it as a work truck/daily driver and doesn't go off road.

 

Another thing to consider is RPM at cruising speed, you want to be under 3,000 rpm as that is generally where the mileage begins to drop off...

 

B

Link to comment
Share on other sites

Yes, correct.

 

Sorry I failed to see that you have an R50, so my friends WD21 anecdote doesn't really apply. Let me try to make up for it...

We have a R50 SE with Yokohama AT/S 265/70/15 tires (29.5x10.5") on the stock aluminum rims.

I mounted some BFG AT/KO 31x10.5x15" on steel 7" Cragar Soft 8s that weighed 8 or 12 lbs more? (can't recall but I know I posted it here)

Mileage and acceleration around town went down, as well as ride comfort. The 70 mph cruise dropped to about 2,300 rpm IIRC (will try to find the info) which was nice for the flats and turning off the OD on hills.

The R50 is a 1999.0 automatic with 4.63 gears...

The Yokohamas went back on and I'll use the others for my WD21 as daily driver meats

 

B

Link to comment
Share on other sites

Honestly there is nothing wrong with 30" tires. Infact, on the contrary, I'd say it's a little more than debatable. Guys being guys of course we like the look of a larger tire and that little bug in our brain that tells us that with more diameter and a larger footprint, we can go over and through offroad terrain / obstacles / muck better than with smaller tires. I'm guilty of all of these, I went from 235 /15s to 31" 10.50 /15s and I'm soooo glad I did and still I want more, the tire bug is continually eating my brain telling me that I need 32 x 11.50 /15s....they'd look awesome! Yes, they would and I might get a tiny bump in ground clearance.

 

But there is a trade off that nobody wants to talk about: Bigger tires raise your final gear ratio, which lowers torque. If you do all your offroading in 4 low, then I doubt this would ever be a problem, but for daily driving it would start to become an issue maybe around the 33" mark. Acceleration and gas mileage will go down. The bigger tires will start to tax the little v6 in some situations if wheeling in 4 High. Also, bigger tires are heavy. Going too big will have those heavy tires putting a lot of extra stress on the hubs, steering linkages and tie rod ends / ball joints that it really wasn't designed to handle.

 

Where as if you're running 30" tires, you'll have a lighter tire and more torque, easier on the engine, hubs, wheel bearings and gearing / drive train. Plus the skinnier, lighter tires I believe cut through the muck a little better cuz they go straight to the bottom of the soft terrain where as a larger foot print will ride on top of the muck more so than down in it. A 30" tire will get traction and go over stuff the same as a larger tire, (not to mention you'll have more power) however if you're in sand you wont get the flotation benefit that you do with a larger tire with more surface area to "float" across the sand.

 

As far as I can see the only real drawback with the 30" tire is the small tire look, and a slight hit on ground clearance. If you were to maybe do a 2" - 3" lift it would solve your ground clearance issues and leave you looking a little silly...but seriously, how many Billy Bad Ass jocks with huge tires have we all seen suckin mud and needing a winch out. There is something to be said for lighter weight, skinnier tires and a little more torque than you'd have with larger tires. It's all science Baby.

  • Like 1
Link to comment
Share on other sites

The only thing I will point out is that Pathfinders were available with both 235/75/15 tires on 6" steel wheels and 31x10.5x15 tires on 7" aluminum rims, but there are no differences in part numbers for things like ball joints, tie rod ends, etc. This strongly indicates that the suspension and drive train is engineered for tires of at least 31" size.

Yes, I do believe 33" tires, especially 12.5" wide, put extra wear on stock components, but a lot of people have upgraded other components as well just to be able to run them so it seems to work out ok.

 

I run 31" tires, best of all worlds for a daily driver version of this model for me.

 

B

Link to comment
Share on other sites

if im correct, bigger allows for lower rpm at higher speeds?

 

Yes but dont forget about the mass of the tire. A larger tire may be heavier therefore take more power to spin and keep it spinning and in turn use more fuel at a lower RPM.

 

 

I run 235/75/15 BFG AllTerrains. They are roughtly 30" tall. To me, they look too small. Planning to see what 31s look like under it for the next set.

 

I dont have too much knowledge on the R50 other than my aunt runs the exact same 235/75/15s on hers as I do on my HB.

Link to comment
Share on other sites

Yes, correct.

 

Sorry I failed to see that you have an R50, so my friends WD21 anecdote doesn't really apply. Let me try to make up for it...

We have a R50 SE with Yokohama AT/S 265/70/15 tires (29.5x10.5") on the stock aluminum rims.

I mounted some BFG AT/KO 31x10.5x15" on steel 7" Cragar Soft 8s that weighed 8 or 12 lbs more? (can't recall but I know I posted it here)

Mileage and acceleration around town went down, as well as ride comfort. The 70 mph cruise dropped to about 2,300 rpm IIRC (will try to find the info) which was nice for the flats and turning off the OD on hills.

The R50 is a 1999.0 automatic with 4.63 gears...

The Yokohamas went back on and I'll use the others for my WD21 as daily driver meats

 

B

The stock size Yokohama tires run at 2,500 rpm at 68-70 mph, just checked it today.

 

B

Link to comment
Share on other sites

There are some excellent articles on Expedition Portal regarding tall and skinny tires, but the jist is that they yield a larger footprint when you air down. I have ~30.5 x 9.5" on my pathfinder, and have not found an effect on mileage. They are actually lighter than the tires they replaced, yet are 1.5" taller, meaning I got a .75" lift, and no mileage penalty. The majority of mileage issues are related to weight, and ride quality issues are related to tire design, not size (unless you're going low profile). Typically however, a higher aspect ratio tire (taller overall with a larger sidewall) will ride smoother over rough surfaces than its lower aspect ratio equivalent. Taller tires will affect your speedometer readout, as well as odometer, among other distance-based calculations your car will do, but only by the percentage larger than the stock tire you're running. My speedo is 3% off for instance, because I installed a 3% larger tire, meaning the indicated speed is actually 3% less than actual speed. With my 4.63 stock rear end and these size tires, doing 80 mph yields about 2.9k, anything lower and the mileage is tolerable.

 

I would say go tall and skinny because they strike a nice balance between ride quality of the taller tires, and better fuel economy and fitment of a skinny tire, plus when wheeling they can "cut" their way to the bottom of many surfaces quicker, yielding better performance on FS roads, thin mud, rock, and others. As long as you don't go for giant wide meats on heavy rims, you won't be sorry. ;)

Edited by Karmann
Link to comment
Share on other sites

  • 3 weeks later...

The only thing I will point out is that Pathfinders were available with both 235/75/15 tires on 6" steel wheels and 31x10.5x15 tires on 7" aluminum rims, but there are no differences in part numbers for things like ball joints, tie rod ends, etc. This strongly indicates that the suspension and drive train is engineered for tires of at least 31" size.

Yes, I do believe 33" tires, especially 12.5" wide, put extra wear on stock components, but a lot of people have upgraded other components as well just to be able to run them so it seems to work out ok.

 

I run 31" tires, best of all worlds for a daily driver version of this model for me.

 

B

With my 33x12.5's I find my truck eats idler arm bushings and upper ball joints. That and it will gear down to 3rd climbing any grade in a headwind. I got some 265 75 15 winter tires from a family friend that I got mounted this weekend. I am looking forward to having some mileage and power back, LOL.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...