Tire Pressure question from a new guy

[KC8RXQ]

We took delivery of a 2010 F350 CC/SRW Lariat a couple of weeks ago. It's my first Ford and my first diesel and without a doubt an awesome truck. My question concerns the tire pressure to run when the vehicle is used as a daily-driver. The B-pillar indicates 65 psi on the front and 80 psi on the rear tires but the ride is pretty stiff. I emailed Continental and Ford and only got their stock, by-the-book response referencing the 65/80 psi tire pressure ratings on the sticker. The local dealer said his customers typically lower the rear tires to 65-70 psi and increase the pressure if they are going to haul/tow anything significant. My question to the forum is...will there be any adverse effects to lowering the rear tire pressure to match the front tires? We will be taking the truck on a long trip soon and will have five adults along for the ride. Thanks for the help. I've joined the forum as a premium member and have really appreciated the information you put out on the forums for all of us to see.

Regards

[superdutydixie]

First off welcome to the ORG!! The only thing that might come up with lower the tire pressure is you might get a pressure light on the dash or something. In that case just air up the tire a little more or deal with the light on. I can't imagine any adverse effects caused by lowing the tire pressure a bit from what the sticker says.

[Dietoremain]

I have my front and rears at 75 PSI and yes it does give a stiff ride, but honestly it makes your tires last longer.. lower is comfier i know. haha.

[BlueF350]

As a daily driver I use front 70 front and 75 rear. I air up the rears to 80+ if I'm towing. IMO 65psi is too low for the fronts and they feel mushy.

[Delta Jim]

I find the 65 psi up front to be fine (there's a pretty heavy diesel engine directly above) but running 80 psi rear with an empty bed is unnecessarily high in my opinion (and quite a bit firmer). On my '09 F-350, the TPM seems to alert at pressures under 70 psi (rear) so I drop the pressure to 70 psi when empty. I air up and down according to the payload and if I'm towing.

Safe bet is to follow the recommended pressures but I am thinking Ford assumed a max payload when denoting the 80 psi rear tire pressure.

Enjoy the new truck,
Jim

[smotrs]

Best way to check what the tire PSI should be is to use a grease pen on the tire across the treads. Then roll the vehicle forward a few revolutions to see how it wears. if it wears the mark off evenly then your at the correct PSI to have proper tire wear. If the outside edges wear before the center, then its under inflated, center before the outside then your over inflated.

If you find that the PSI is significantly different then what the pillar sticker shows, you'll probably end up with a TPMS warning light, but you'll at least know what the correct PSI is for your tires at your current load conditions.

[BlueF350]

Originally Posted by smotrs

Best way to check what the tire PSI should be is to use a grease pen on the tire across the treads. Then roll the vehicle forward a few revolutions to see how it wears. if it wears the mark off evenly then your at the correct PSI to have proper tire wear. If the outside edges wear before the center, then its under inflated, center before the outside then your over inflated.

If you find that the PSI is significantly different then what the pillar sticker shows, you'll probably end up with a TPMS warning light, but you'll at least know what the correct PSI is for your tires at your current load conditions.

That's a cool idea!!