Another stupid question

Murnan998

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I know this is a dumb question and is probably posted somewhere here but I cant find it. What does the marking " TP 20" on the front fenders of my 1993 M998 mean. Thanks for the info.
 

juanprado

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many opinions on tire pressure. IMHO, if you are doing interstate/highway driving, i would bring them up to 30-35 psi. Tires are rated for it. No modern tires going on the interstate speeds are inflated so low. Low presuure increases traction but at highway speed they drastically increase the heat load leading to blow outs.

I run 35 on bfg all day long on interstate with no problems.

Stay safe
 

Ajax MD

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At first, I thought those tire pressure markings reflected the old bias-ply tires and the fender markings were never updated. Then, I dug into the Operator's Manual.

Table 2-2, Page 2-91 in the -10 Operator's Manual lists all the tire pressures for the various models for RADIAL tires.
The tire pressures listed are still quite low in my opinion, especially when you consider how thin the sidewalls on the Wrangler MT's are.

The line: "UNLOADED* All Models- 15psi/Front and 18psi/Rear" seems especially low to me.
Then, at the top of the page it simply says "Do not exceed 50psi cold tire inflation pressure."

On the Wrangler MT's, 30psi on an unloaded or partially loaded truck, running on the highway seems to be the sweet spot for traction, fuel economy and not overheating the tires.
 
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TOBASH

Father, Surgeon, Cantankerous Grouch
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Let’s remember our history...

Ford Motor Company suggested 20PSI for tires on its SUV’s many years ago. Tires exploded and the SUV’s rolled over and the SUV’s “A” beams were weak so plenty of people were killed and maimed. Lawsuits raged and the tire manufacturers said in court that the tires were designed for 30 and not 20 PSI and they said Ford got it wrong and gave out incorrect information and used the tires outside of specs.

Our FMV’s also have weak “A” and “B” Pillars. They are not meant to handle a rollover. We don’t have rollbars. Unless you utilize runflats and have a strong faith in God, Only Goodyear specifications should be utilized. Even then, Goodyear specs should be used. I’m sure Goodyear has those specs online somewhere. I would not trust AMG specs as they are not the rubber manufacturers.

My uneducated guess... Unless you’re wheeling off-road at extremely slow crawling speed and air down for traction, I would suggest running much much higher than 20, BUT I am not educated in this and this is my personal guess and is not based on literature or fact. Proceed at your own risk.

IMHO, I suggest you and this whole community research this carefully before driving.

Best,

T

PS-Maybe RWH has a perspective???
 
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Chief B

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Milton, FL
Thank you for this thread... I had mine at the 50 that it says on the tires and my ride was rough as could be... after reading this I dropped it to 40 and it is much smoother now. Will be dropping another 5-10, but started with 40 (mainly because my son aired down for me and was easier to tell him 40 rather than to explain to him how to read something that is not digital...lol)
 

diesel dave

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This has been discussed in the past. The ratings on tires are the maximum psi allowed for the stated maximum loaded weight. In other words,unless you’re planing on carrying around a couple of thousand extra pounds,you would not inflate your tires to the maximum psi. Doing so would only give you a rough ride and wear out the center of the tires. The danger of blowing out the side walls comes into play when the load has been increased without increasing tire pressure.
 

osteo16

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just put em at 30-40lbs of pressure and either like the ride or not.. up--stiffer, lower--softer... like any other vehicle.. just my 2 cents
 

Inspector 1

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I keep 40 psi front 45 psi rear. Run flats removed. Does very well on freeway. Not a lot of off road as I live North of Houston Tx. which is a concrete jungle. (LOL)
 

TOBASH

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I keep my runflats in. I do this to prevent differential damage if I air down at speed. Also allows me to drive off the highway to do repairs vs. losing my legs or my life from bumper injuries at the side of an active hway.
 

Inspector 1

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Spring Texas
I keep my runflats in. I do this to prevent differential damage if I air down at speed. Also allows me to drive off the highway to do repairs vs. losing my legs or my life from bumper injuries at the side of an active hway.
That is certainly a great point in keeping the run flats in. I cringe every time I see someone on the side of a Freeway changing a flat tire. If we think that one little white line is going to protect us from a distracted driver, statistics would say otherwise. I always tell my wife if you get a flat tire no matter what , exit the freeway to the nearest parking lot. I can always buy a new rim. If I had a complete blow out on the HMMWV, because there is so much rubber, would I be able to drive on just the rim or would the under carriage and for that matter even the body be dragging on the ground?
 

TOBASH

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These are 16.5 inch rims but they hold 37.5 inches of rubber. Just look at a picture and you will see what happens if you’re left with just a rim.

If you air down lots of bad things can happen, including a rollover. I know lots of people remove the runflats to diminish rolling weight BUT there are some very good reasons to leave them in. Our mileage will never be great so what’s a little less due to run flats?

IMHO

Best,

T
 
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