Ok, today, I bought a huge quantity of marble and travertine tiles, without thinking for a moment about what this order was going to weigh. As we were finishing up loading this order (19 boxes of travertine @ 55lb per box, and 45 boxes of marble, weight per box unknown) onto the minitruck, I noticed that the tires were sagging so bad under the weight, that they looked nearly flat. I idled in 1st gear to the tire area at the Costco I bought the stone tile at, and we upped the pressure to 50 psi. They were still sagging hard under the weight, but the truck was able to at least be driven (slowly) to work. The weight did expose a slow leak in one of the rear tires, so I also had to stop at wal mart for some fix-a-flat to quickly stop the leak. I called my neighbor and asked him to head out to where I work, and we offloaded the marble into his pickup. So, I'm at least down to a "doable" 1047 pound load in the truck, instead of something that in all likelyhood weighed more than the entire truck did by itself. However, I have yet to see any 145r12 tires with a maximum pressure rating on the sidewall. So, my question to those who know is, what is the maximum SAFE pressure rating for these little street tires? I'd like to be able to make any needed adjustments to the pressures before I leave from work on the 50 mile jaunt home. TIA.
I have never seen two alike. They have been as low as 22 and high as 65 depends on the manufacturer, load range, speed rating, typically 32 to 36. There has to be a # on it somewhere for cautionary mounting purposes and DOT requirements.
Stock tires are 145R12 tires. As an update, I'm now home. I drove home with the rear tires still aired up to 50 psi, and kept my speed to a max of 45 mph. I stopped to check them about halfway home, and they were literally cool to the touch. I was also able to weigh a box of the marble tiles. They weighed in at 27.8 pounds each. So, at one time I had 2,298 pounds of stone tile loaded up in my truck. Gotta love short gearing. The truck actually moved that weight for a few miles with little difficulty. I am DEFINITELY glad that I did not attempt do drive home with the entire load on the truck. 5th gear was making a rather sinister noise as it is, by the time I got home with less than half that weight left on the truck. I did take the minitruck for a quick spin after offloading the travertine, and the noise was gone, so hopefully, it was simply from the driveshafts being out of whack from the weight. I'll be keeping a close ear on the trucks noises for a while, to make sure that I didn't do anything to hurt it.
That would be the case if these were U.S. sold tires. Mine are take-offs from another minitruck that got a tire and lift upgrade.
Wolf, My dad owned a tire store/garage and in college I was "free labor"...grew to hate that business. All tires (usa) have a load range on the side of them. A=2ply b=4..you get the picture. TYPICALLY (by memory) pressures are as follows; A=28 B=35 C=35-40 D=45-55 E=70 max These may be off of a few pounds because my memory ain't what it used to be...now what were we talking about?
I appreciate the help. These are not U.S. spec tires. They have no code on the sidewall, just a date of manufacture stamp, and maufcturer name, and tire size on the sidewall. What I was hoping to get was an answer from one of our Japanese members, on what the manufacturers consider is an acceptable maximum pressure. While I got home without incident last night, I'd like to notate it for the next time I find myself loading this truck up to its limits.
Wolfman, I noticed that on my door jamb there is a sticker with pressure data. Maybe someone that can read Japanese can tell us what the columns are. I assume front/rear or somesort. 2.4 kg/cm2 = ~35psi. 2.0 kg/cm2 = ~28psi. 3.0 kg/cm2 = ~43psi. Edit: I'm thinking it means Unloaded- 2.0 rear 2.4 front. Loaded 2.4 rear 3.0 front.
Update: I also found a warning on my 145/70 R12 Bridgstone Blizzak. States "Do not exceed 40psi" -Greg
Thank you, this was exactly what I needed to know. Thanx!!! I'll have to poke around and see if I can find a similar looking label on mine someplace.
Mine are dunlops, but I probably did have them over limit for the tire. I did keep my speeds down to 45 mph on that drive home, and the tires stayed cool to the touch. I'm still :frustration: myself over being so stupid as to not even consider the weight of the sheer quantity of tile that I bought. I will NOT repeat such a stunt again.
