OK, now that "Lurch" has had his suspension upgraded, it was time for some new shoes.

Goodyear AT/S 285/75R16s, panhard drop bracket welded in place and an alignment done on Friday. It's getting close to being as done as it's going to be for awhile (see pic attached.)

The AT/Ss are an 8-ply tire with a maximum pressure rating of 65psi. When I picked up the truck after having the work done, I was told that they were inflated to 50psi (not used to hearing tire pressures that high!)

I immediately noted how "mushy" the handling was -- lots of sway that I'm not used to with this truck. It was disturbing. Felt kinda like driving around on nearly-flat tires. I checked the pressures when I got home and found them to be 43psi all the way around.

Knowing that the taller tires are going to be a bit mushier, it was more than I was willing to accept if not necessary. I increased the pressure to 50psi and it improved somewhat. I can live with it now.

However, since these are not the stock (recommended) tires and are entirely different in their rating and construction, how can I find out what pressures are acceptable with this tire on my truck? Lord knows, I don't need a blowout because of over-/underinflation!

The archives have lots of tire pressure recommendations for 265s, but I found scant little about 285s.

Anyone out there running the same tires and have some recommendations?

Thanks,

Don

 

Hey Don, looking good. you didn't tell me you got some shackles as well. My hangers should be ready one of these days.

I run my mudders at about 33 all the way around.

 

[HIJACK ON] One of these days...just waiting on some more material and beggers can't be choosy! I got one cut out from scrap, just waiting on some more 2" tubing to float over to the scrap pile. [HIJACK OFF]

I'm somewhere in that range as well, 34-36 psi hot.

 

lighten up young hare! I wasn't implying anything

 

I know!!! Oh, but it is so much fun to poke at you with a sharp stick!

I can't imagine my MT/Rs pumped up with that much air, 45-50 pis. They would truly be as my co-worker calls them the "Goodyear Blimps".

 

That's what I'm trying to find out, Waskilly ... they don't look bad at all at 50psi. They look normal. If I deflate them to 35, I'll be squirreling all over the road!

I was hoping that someone on the forum is running 285 AT/Ss and could shed some light on the problem. I'm not sure if MT/Rs are built the same. I've never had a tire that had a 65psi max (except maybe on a bicycle.)

I guess I'll wait and see what Mr. Goodyear has to say -- assuming anyone ever answers my e-mail ...

-- Don

 

Well I've got 31's and I am running mine at 35psi all the way around (hot) so I would assume that since yours are quite a bit bigger than mine you would be in the 40-45 range but I am definately NOT an expert on this sorta thing.

Truck is lookin good there man!

Fink

 

When I had Nitto 285-75-16's I ran around 45 psi.

I had a guy come into my office today showing off his new Nittos and wheels. He said the tire guys had him around 55+ psi. He let some air out and went with 50psi (on an 8 inch wheel).

Doug M.

 

Well, gee Don, looks like maybe I'll pump mine up to 45 and try that for a while to see how mine runs. it seems alot of people are running in that range with the 285's. I think I'll go out to the garage and fill them up after the game tonight.

 

I run 35 lbs. in my 285/75/16 BFGs. Anything more and it's a rougher ride.

 

Well, as a followup, here's the response I received from Goodyear when asked what their recommended pressure would be for my vehicle and their tires:

"Thank you for contacting our web site. Operating air pressure is determined by the vehicle manufacturer.

If you're using the same size tire that came as original equipment on your vehicle, the proper air pressure is indicated on the door placard or owners manual of your vehicle.

The air pressure indicated on the sidewall of each tire is the inflation pressure required to carry the maximum allowable load for that tire.

Vehicle manufacturers have invested considerable time and testing to establish an air pressure that will provide a smooth comfortable ride in addition to an even tread wear pattern.

Our recommendation would be to stick with the air pressure established by your vehicle manufacturer."

I'd say, given the recent furor over blown SUV tires, they've covered their assets rather well with that advice.

Any bets that if I contact Toyota with the same question, they'll refer me to Goodyear for advice?? :cry:

-- Don

 

Take a business card and draw a line approximately 1/4 inch from the edge. Park your truck on a flat, level surface. Air the cold tires up or down until you can slide the card under the side of the tread to the mark.

I can't recall where I saw this technique, but it works for me, and I'll buy a beer for the guy that figured it out.

The BFGs on my 98, and the new ones my 03, wear perfectly flat and have no squirm. The tire dealer recommended stock pressure, but both trucks squirmed badly there.

My 03 ended up at 40 front, and 38 rear, but the 10 ply BFGs on my 98 were more.

 

Thanks, Bill. I'd read that trick on another post and was planning to try it if all else failed. I just thought I'd at least give the manufacturers a crack at it first.

Right now I'm on hold with a Toyota rep. He's "surprised" that Goodyear passed the buck, but he's checking on the information and, I suppose, whether legally he should provide any assistance at all since the tires are non-standard.

I'll post Toyota's response as soon as I get off hold ... :pat:

-- Don

 

Roger Brown's site

I saw it someplace else also but I can't find the site.

I run my 285/75 BFG ATs at 32 PSI on the road.

 

I don't know why but that word has always bugged me. Call me weird but it is just a strange word in my book.:alien:

 

Well, there's always the southern spelling for PLACARD ...

PLACKERD



Anyway, here's the end of the Tire Pressure Saga ...

"Jason," at Toyota (800-GO-TOYOTA ... and make sure you punch in the right numbers. I didn't and got some sexy voice advising me that if I wasn't 18 or older I should hang up!) did some checking and decided that it wasn't in Toyota's best interest to advise me on tire pressures since Toyota has never tested 285s on their vehicles. He recommended that I contact Goodyear again and tell them that Toyota couldn't make any recommendations on tire pressure for their tires. Gee, what a surprise.

So, there you have it, folks. If we put anything other than the recommended tires on our rigs, we're on our own.

I have my 1/4" line on a business card ... I'll be using that gauge tonight.

Thanks for all the input, guys.

-- Don

 

This is a another method of determining the correct air pressure for your tires.

Find a nice flat dry concrete lot.
Wet the ground.
Make sure the tires are overinflated and slowly drive through the wet patch.
Now checking each tire one-by-one, air down until you see a copy of the full width of the thread on the dry ground.
Once you have the full width you are at the correct pressure.

This method will take quite a bit of time, but if done correctly, will give you the exact air pressure for your rig. And it works for every weight, spec etc.

 

I'm just going try the bidniss card thing too and then hookup the ol' sweedish made pump and inflate the tires. however, on the dirt it goes back down to 15-20.

 

Well, here's the final instalment of the saga ... I promise!

I contacted the Goodyear rep via e-mail, explaining that Toyota would not issue any pressure recommendations because they'd never tested 285s on 4Runners. Understandable, since they won't FIT on a stock 'Runner.

Anyway, here's the Goodyear rep's response:

"Thank you again for your response.

I am sorry I cannot answer your question as air pressures are determined by the vehicle manufacturer and not the tire manufacturer. Air pressures are determined by the size and weight of your vehicle and are listed on your car door panel or owner's manual, which is provided to you by Toyota.

Per the 2003 Tire Guide, Toyota recommends 32 psi on both your front and rear tires.

Again, I apologize we cannot give you an answer to your question, as Toyota establishes the tire pressures for their vehicles."

So, I politely thanked her for not helping and advised her that, in the unfortunate event of an accident resulting in my demise, my heirs will probably sue both companies and they can battle it out in court!

Oh, well ... I tried. I guess I should make ONE MORE POST on this topic for archival reference. After I use the "1/4"-on-a-bidness-card" technique, I'll post the resulting tire pressures.

-- Don

 

haha, now there's the sarcastic Don I know! haha, just make sure you print out those emails and file them in the fireproof safe.