26PSI for a long trip - Risking a rollover?

[RaDiKaLBoArDeR]

I know this has been posted before but after a 30 min search I haven´t been able to find the answer I was looking for so here it goes:


I am planning to do a 900 mile trip this weekend with a fully loaded car. I will transport something like 2000 lbs.
The weather here in Europe is right now the typical autumn weather. Rainy / Sunny and 60 Degrees F.
I will be driving only on good asphalted highways.

I have a 97 XLT with the Firestone Wilderness AT tires 235 / 75 / 15. These have only 3000 miles on it (dealer gave me those until the new Michelins arrive)

My question is: what tire pressure (PSI) do the tires need to be inflated at ?
They are at 26 now, but I have read that this is meant to be too low.


Thank you in advance !
Marc

 

[Robert]

I think Ford is recommending 30 PSI for anyone with the Wilderness tires still on. Since you will be traveling at higher speeds with a heavy load, 30 would be the minimum. I certainly wouldn't try 26.

 

[JDraper]

I'd run 32-35 PSI. Ford recommended the lower pressure so the vehicle would ride smoother. Whatever is on the sidewall is what I would put in. That is what the tire is rated for. If I remember correctly, the wilderness tire is rated for 35PSI.

For some heavy duty tires (like my BFG T/A's) they have a higher pressure on the side, but 35 seems to be the norm for most tires.

 

[RaDiKaLBoArDeR]

Thanks for the reply guys!
Should I put the same amount of PSI on all 4 tires or do I need to put more in the back ?

 

[JDraper]

Use the same pressure all the way around. It'll handle better.

 

[Robert]

Under most circumstances, you should NOT fill your tires up with the PSI on the sidewall. That is the absoulute maximum amount of air you can put in your tires. Firestone doesn't list their tire weight specs so I checked the Michelin LTX M/S P series. It is about as close, specification wise as you can come to the Firestone. I checked the 105S rated 235 75R15 tire. It has a maximum weight of 1844 pounds per tire at 35 PSI. Unless you are going to have a total of 7376 pounds on your four tires, 35 PSI is too much. If you did weigh in at 7376 pounds, your would greatly exceed your GVW. Depending on how much of the 2000 pounds you are hauling is in the Explorer would dictate how much air to put in your tires. I would start at 30 PSI and maybe go up to 32 PSI if you have a lot of weight on. Here is a quote from Firestones's website regarding tire inflation:

"Although the sidewall of your tire indicates a maximum pressure figure, this number does not indicate the proper inflation for your car. Rather, it indicates a top pressure that you must not exceed for any reason."

 

[JDraper]

Well, with a curb weight of about 4150lbs, and 2000 lbs load, thats over 6k lbs. You're getting up near the max weight you mentioned. If the weight is cargo, and most of it is in the rear, you're gonna be real close to that max weight per tire on the rear tires. I'll stick by my 32-35 psi statement for that weight. HOWEVER, 2000lbs is WAY over the rated load capacity of the 1997 Explorer, which is about 1050 lbs. I'd suggest you put a hitch on the back and carry the load with a trailer. Much safer.

Data came from http://carpoint.msn.com/Vip/Specifications/Ford/Explorer/1997.asp which is for the US version of the X. I'm not sure what the specs are for a european version, but they should be similar.

 

[RTStork]

I agree on the 32-35psi.

 

[RaDiKaLBoArDeR]

Thank you very much for all the replies!

 

[Robert]

Originally posted by JDraper
Well, with a curb weight of about 4150lbs, and 2000 lbs load, thats over 6k lbs. You're getting up near the max weight you mentioned. If the weight is cargo, and most of it is in the rear, you're gonna be real close to that max weight per tire on the rear tires. I'll stick by my 32-35 psi statement for that weight. HOWEVER, 2000lbs is WAY over the rated load capacity of the 1997 Explorer, which is about 1050 lbs. I'd suggest you put a hitch on the back and carry the load with a trailer. Much safer.

Data came from http://carpoint.msn.com/Vip/Specifications/Ford/Explorer/1997.asp which is for the US version of the X. I'm not sure what the specs are for a european version, but they should be similar.

Well, he mentioned that he "will transport something like 2000 lbs". I didn't think he would try and put it all in the cargo area. If he did then yup, he would be way over the cargo capabilities. If he put it on a trailer then the only added weight to his tires would be from the tongue weight.