It's been awhile since I've been on her since I bought my bike. I don't take my truck nearly as much anymore, basically only when it rains or when I need to bring big things with me like hockey gear.

The ABS and Brake lights came on 2 weeks ago and ended up bringing it to the shop. Well some of you might remember my whole thread about my truck being slow and we pretty much blamed it on my 285's with 3.55 stock gearing.

Well the shop recommended I throw new tires on since the ones I had on didn't have much left and one had a hole in it that made it go from 65 to about 30 psi every day.

I ended up getting Cooper Geo-Trac 265's. They basically chose these tires without me so I was a little disappointed with that, I would have like a more aggressive tire, but anyway, I was really hoping to get that acceleration my friends have in their trucks.

What a disappointment, the truck performs exactly the same as it did with 285's on it. I don't understand how my friends 5.2 same year, 265's, stock gearing I'm assuming, is so much more powerful than my truck after the mods I've done.

So about the tire pressure, I looked at the tire pressure when I got home from the shop since they looked to be low (the little bulge on the bottoms) and they filled them up to about 35 psi which is what it says on my doorjam sticker. The tires themselves say 80 psi. My old 285's said 65 psi and that is what I filled them up to. Should I go with 80 psi or 35 psi or something in between just so they aren't sagging?

 

i put in what the tire say,,, so if it said 80 i would put in 80

 

Leave them around 35-40 PSI whenever you're not towing or hauling anything in the bed.

If you put 80 psi in them you're not going to have any center tread left very shortly.

If you look closer you'll see that 80 psi is a maximum inflation rating.

 

80 PSI will not cause any abnormal tread wear. The company would not be able to put 80 PSI on the tire if it wore the tire faster than normal because they would be called out on it.

OP: You alone are the reason for whatever pressure you want. The more pressure you have, the harder the truck will ride and the less, the softer.

 

I would tell them to take the tires and stick them where the sun don't shine!! Why did u let them get the tires? I run mine at what the door say with mine is like 41 PSI.

 

And you don't notice any bulge on the bottom of them? What size are yours?

 

If you run the maxium rated PSI, you will get abnormal tread wear. Trust me, been there, done that. The companies would not get called out on abnormal tread wear. They would get called out if someone put 80 PSI in an 80 PSI tire and it had a blow out later. Thats pretty much the only reason the PSI rating is there, to prevent blow outs.

That being said, it does depend a bit on the tire. My tires have a maximum rating of 45 PSI, and I run 36 PSI in the rears, 38 in the fronts.

 

i would experiment with the pressures a bit, between the trucks sticker pressure and the tires max pressure. the lower the pressure, the softer the ride. higher pressure, you will see a stiffer ride but increased handling and fuel economy. i find my truck is the best at 60psi front and rear until i get a load on, then the rear gets 75psi.

 

80 PSI is way too much unless your maxing out the load on your truck. At 80 PSI each tire can probably support 3,000 lbs. Does your truck weigh 12,000 lbs? If so, use 80 PSI.

My 96 Ram came with 225's and the sticker said to use 41 PSI. I changed to 245's and used 41 PSI, with a result of the centers wearing out real fast. I looked in the manual and it said the proper PSI for 245's was 35 PSI. I have been using that and the tires are wearing even.

Pro's to using higher PSI
Higher mpg's due to smaller contact patch and lower rolling resistance.

Con's to using higher PSI
Reduced contact patch area results in decreased braking performance. Safety hazard.
Tires wear uneven.

That buldge on the bottom is normal for tires. Just because there is a buldge does not mean that the tires are under-inflated.