Too much tire on my LC100?

[The Adam Blaster]

I had load E's on my Tacoma and did just fine although it was a little rough. I kept around 31-32 psi in the tires. I was told by many a tire salesman that wasn't the thing to do as it leads to the tire becoming out of round. The last year I had them on my truck, I couldn't keep them balanced to save my life and the front end shimmy was becoming dangerous. I switched to load C's and it's like riding on a magic carpet. I would have bought D's if the Duratracs were available in that load range but I am happy overall.

Some more tire tech generalizations from me...

The jump from D's to E's really isn't that big, they usually have close to the same rated capacity but the PSI limits will be higher with the E's, but honestly not that much. (Pretty much the entire industry is starting to move away from the D's since they are becoming redundant, most guys that have 3/4 trucks want/need to run the E's anyways.)
Originally, the standard convention followed this pattern:

1/2 ton truck = C
3/4 ton truck = D
1 ton truck = E

Now that the 3/4 trucks are rated so much higher compared to earlier years, most require that the owners keep the E's on them.

Here's a quick example of what I'm saying regarding the load ratings between D and E tires straight from the manufacturer's 2010 data book:

Goodyear Wrangler MT/R with Kevlar <- so fancy lol
LT275/70R17 E rated for 3,195 lbs @ 80 PSI
LT285/70R17 D rated for 3,195 lbs @ 65 PSI
Ideally the tire size should be the same, but those are darn close, and as I eluded to before, the offerings in D tires are getting eliminated by E's.

Another comparison, same model of tire:
LT265/70R17 C rated for 2,470 @ 50 PSI (around town running these at 35does decrease the total load rating but gives a better ride)
LT265/70R17 E rated for 3,195 @ 80 PSI

Now, regarding running E tires on a 1/2 ton truck or lower, chances are running at ~ 35 PSI may very well end up with uneven wear and balance issues towards the end of the life of the tire. The tire wasn't really designed to be run at those pressures.
Looking at the ratings I've posted above - running the C rated tires gives you a total weight rating for 4 tires at just about 9900 pounds. How many of you guys with Tacomas or Land Cruisers load your rigs up with so much gear that your total weight is over 10,000 pounds?
So, bearing that in mind, it's clear you should really be looking at staying with the C rated tires on these sized vehicles.

 

[Mike S]

The PSI on E rated tires is max inflation. I run Toyo M55 E rated tires on my Ford F350 Superduty. They are at 55 PSI unloaded and at 65 when towing my Airstream.

I had the truck at the Ford dealer for some maintenance and the tech saw the '80 PSI' on the tires, and started to inflate to max, assuming the tires were low and out of spec. You would think a Ford dealer mechanic would know something about truck tires. If they were run at high pressure they would be harsh, and the center tread would wear quickly.

I have been thinking of dumping the Revos on the LC and putting Toyo M55 on that too, in order to have tougher side walls, but I am concerned about highway ride comfort.

 

[ShottsCruisers]

I'd be curious as to which rear springs you have? 863? 864? On an unloaded truck your rear would be WAY in the air. Then IF you match the front to the rear your front is WAY too high and your ride will suffer as well.

Which springs do you have?

 

[Nay]

So, bearing that in mind, it's clear you should really be looking at staying with the C rated tires on these sized vehicles.

The problem is our 16"/17" rims. While you can find big tires in C Load Range for 15" rims all day long, 16" in particular is a "LT" size and the tires are almost universally designed more for the big pickup truck market than the offroad market.

I'd love to be able to run 15's as that would open up a huge range of wheels and tires, but they don't clear an 80's front calipers. I'm not sure going up to 17's helps, as 17's are really just the rim that 16's used to be (bling) for the same applications so you are still getting the D/E applications.

Still, somewhere in the 42-45 range PSI for a tire that isn't a huge offroad chunk of rubber like mine is probably going to be the right balance of PSI to longevity if you want to stay a bit on the higher side.

 

[bunduguy]

I'd be curious as to which rear springs you have? 863? 864? On an unloaded truck your rear would be WAY in the air. Then IF you match the front to the rear your front is WAY too high and your ride will suffer as well.

Which springs do you have?

I believe I'm on 864's. But will have to check. All I remember is that they're one step down from the stiffest. I cannot find the packing list and forget which ones Kurt from Cruiser Outfitters ended up recommending.

 

[ShottsCruisers]

WOW! 864...holy CDKGBUTGGPBKFB. It's not your tires!

 

[bunduguy]

WOW! 864...holy CDKGBUTGGPBKFB. It's not your tires!

Anyone want a brand new set of OME 864's?

 

[spressomon]

Anyone want a brand new set of OME 864's?

Are you sure they're 864's?! That's an 80-series 3.5-4" lift spring. Highly unusual you would have those. Having said that I'm running those...but I have TONS of add-ons, 35" tires, etc.

 

[The Adam Blaster]

The problem is our 16"/17" rims. While you can find big tires in C Load Range for 15" rims all day long, 16" in particular is a "LT" size and the tires are almost universally designed more for the big pickup truck market than the offroad market.

I'd love to be able to run 15's as that would open up a huge range of wheels and tires, but they don't clear an 80's front calipers. I'm not sure going up to 17's helps, as 17's are really just the rim that 16's used to be (bling) for the same applications so you are still getting the D/E applications.

Actually, you should be seeing a lot more 265's and 285's tires with the C-rating.
Also, you'll be seeing a lot more P-metric (considered 4 ply) in the larger sizes.

This is mostly due to the lager 1/2 ton trucks that have been coming out in the last few years. The manufacturers see the market of 1/2 ton owners as people that generally use their trucks for daily driving purposes, rarely pull a trailer so they want/need to have a comfortable ride for these owners. Keeping the C or P-metric tires accomplishes this. (For the most part.)

You will have to search out the type of tires that would have a C rating and be appropriate for overlanding/expedition type travel. (A/T's and M/T's)
Those tires are designed for the heavier trucks, the smooth ones are designed for the 1/2 tons and SUV's that rarely if ever step off the asphalt.

 

[Nay]

Actually, you should be seeing a lot more 265's and 285's tires with the C-rating.

That would be a good thing, generally. I am guilty of thinking in the sizes I run, which I know is not typical, particularly for a rig that has eventual overland aspirations that are beyond my usage today.

I'm also running Interco Trxus MT tires (and will continue to do so until somebody can produce something better) and roundness isn't the primary feature for that selection in the first place, something that would not be true for a Nitto in a 265...

 

[bunduguy]

Are you sure they're 864's?! That's an 80-series 3.5-4" lift spring. Highly unusual you would have those. Having said that I'm running those...but I have TONS of add-ons, 35" tires, etc.

Well, when we put the springs in, first words were, "DAMN!". My wife started complaining that the car was harder to get into. We did get over 3" of lift. I love the look, but it is stiff.

 

[mph]

I must be crazy...Kurt just put my lift on...He suggested 864s in the back because of the extra weight. I have drawers, camping gear, water, etc...I also tow a e1 trailer at times...However, I love the ride without all that stuff. I guess it is stiff...hmmm...I guess I like a stiff ride but love it so far. Just got back from the desert and did 300 miles of dirt and gravel roads...loved the ride...What am I missing? I am curious

 

[bunduguy]

I must be crazy...Kurt just put my lift on...He suggested 864s in the back because of the extra weight. I have drawers, camping gear, water, etc...I also tow a e1 trailer at times...However, I love the ride without all that stuff. I guess it is stiff...hmmm...I guess I like a stiff ride but love it so far. Just got back from the desert and did 300 miles of dirt and gravel roads...loved the ride...What am I missing? I am curious

He actually asked me too, what kind of ride I wanted and if I liked a firmer, more positive ride on road in the corners. I do like it firmer. So really, maybe it's the tires that have just put it over the edge. I'm doing 200 miles tomorrow, so I'll report back on my lower pressure.

 

[mph]

I have a 99 with OME lift, slee sliders, arb front with winch, and yakima megawarrior...I run yokoma at 285...(D rated)I bought mine at discount too. They told me to bring them back if I didn't like the ride. Did you get them recently?

 

[bunduguy]

I have a 99 with OME lift, slee sliders, arb front with winch, and yakima megawarrior...I run yokoma at 285...(D rated)I bought mine at discount too. They told me to bring them back if I didn't like the ride. Did you get them recently?

Not too long ago. Problem is I've put maybe 1500 miles on them on the highway.