I did a search on tire pressure for the SD but there was not too much available. I have the 265-75-16 Firestone Steeltex tires ( which I will replace soon because I do not like Firestones truck tires at all) and they recommend on my door tag to put in 45 psi for the front and 70 psi for the rear. when I got the truck from my dealer it came from the factory with 70 front and 70 rear. what is up with this? has anyone tested tire pressures for the best rides and mpg. If so please fill me in on your findings. I know that the door tag has the recommended pressures from Ford for this truck. But I think a little testing might yield different results. Thanks Steve C.

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2002 F250 SD SC SB Lariat V10.
1995 Cobra R model #185.

 

I kept my front at 65 and rear at 70 on my F-250 truck. I can't imagine having only 45 psi. I had the standard Firestone Steeltec AT tires.

 

If you plan on loading up your truck to the limit then follow what Ford says on the door jam. Otherwise 45-55 front and 45-50 for the rear is what I've been using. Those Firestone tires you hate so bad will go 50,000 miles plus if cared for. I'm on my second set and will most likely get another. My only complant is poor wet traction on and off road.

 

I have LT245's -- and the door recommends 50 and 60.

I ran them both at 50 for 25K miles -- until I noticed they were wearing way too much in the center of the tire.

Been at 45 front 40 rear (I run empty nearly all of the time) for a few months -- and ride has improved.

They're a little bit over 50% worn (actually exactly 50% -- not counting the 2/32 at the wear bar) -- so at 32K miles, it looks like I could eek another 20K out of them.

So -- my recommendation is to reduce the pressure by the amount of weight that you're actually running (eg: if your axle is actually loaded at 75% of rated capacity -- then cut your tire pressure to 75% of the door recommendation) -- then fill them to door recommendation when at door authorized GAWR.

 

Thanks for the help everyone. my truck will run with no load most of the time unless I am towing so I will try the 45-50 front and rear for now and see how it goes. 70 psi seems alot for the rear tires with no load on them. 95rcobra.

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2002 F250 SD SC SB Lariat V10.
1995 Cobra R model #185.

 

I'm running 70 psi front and rear. I've just up'd it from 65psi. It's a bit squirrely in the rear at 70 with no load and I'm thinking of dropping the pressure back to 65. At 65psi the ride is kind of ruff but I don't like a mushey feeling ride. I also run these pressures when I'm pulling the trailer.

 

Hey Tina, When I picked up my truck the other day the tires were at 70 front and 70 rear. the front end felt a little strange driving it home like the truck wanted to travel a little bit on the road. I have since brought it down to 50 in front and it feels better. Ford recommends 45 for the front on my trucks door tag. if you are running 70 in front how does your truck feel on the road. also what tires are you running on your truck. I have the Firestone steeltex tires. thanks Steve C.

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2002 F250 SD SC SB Lariat V10.
1995 Cobra R model #185.

 

95rcobra: I'm running the steeltex also. I can't remember the letters after that, two letters and the number 4. I've just now replaced my original tires with new ones. I was gonna wait a few more miles but the Sunday after Christmas I had two flats. I managed to blow the left front tire and the "huge bolt" that flattened it got picked up by the left rear. Made it to the tire store by putting two plugs into the rear and changing out the spare to the front. I thought the tires handled the blowout pretty well and the rear plugs probably would have gone a couple more thousand but I decided to go ahead and get new tires all around. I've not run any pressure less than 65psi, mine handles well at that psi. Front end feels just fine, rear is a little light feeling. Please note that my truck is heavier in the front end than yours (diesel) and my CC might add a little more weight too.

 

R4S... They're a good street/hwy tire. I put over 44K on my original AT's and got a good deal on the R4S's. I haven't had any problems with either one. I'm going to use the R4S's again(if I can find some) in about another month.

 

Look in your the owners manual package. You'll find a leaflet from Firestone explaining the warranty and inflation pressures. There is a discussion about increasing the tire pressures by 10# over the doorjamb values if hauling or driving over 70 MPH for an extended period. I was not aware of this until I stumbled upon this leaflet. FYI- I have 39,000 miles on my 'stones and they seem to be holding up well. I'm not a big fan of their traction in snow, however.
Another thing I discovered is they do not seem to have a mileage warranty, but a 6 YEAR treadwear coverage (prorated, of course). That means if your Firestones wear out before the 6th year, they'll sell you new tires at a discount. Hmmm... maybe they're not so bad after all.

 

I have the 235/85's and run them at 44psi umloaded and 70 psi loaded...

Ride quality suffers on anything over 50psi unless loaded...

 

Read what the tire says on it. The pressure for many All Terrain tires is around 65 AT A CERTAIN WEIGHT LOAD. Usually, 40-55 is the normal pressure you should run. If nothing else the tires will wear a little uneven, and more than likely they will be difficult if not impossible to balance with that much pressure.

 

Well I could swear that my tires said 80psi. No wonder I've been getting such a cruddy ride I read the psi on the door jamb just a couple of days ago and was a little confused as to why there are different ratings in different spots. The tire says this, the door jamb says that, the manual says who's on first. I don't know.
Guess I'll be airing the tires down tomorrow for sure. BTW, what is a load, weight wise, considered in a SD to air up the tires to over 70psi? I usually carry between 500 - 700lbs.

 

Start getting over 10000 and you have a load on it..

No just kidding, I run around 50psi unloaded(diesel), when I put over about 2k on it I go up to about 70psi, anything over 10000 then I go full blown at 80psi....