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So I am a tad confused on the tire pressure for my 2014 F 450. According to the "tires" the cold psi should be 80#. On the door jamb of the truck it estates front tires cold psi should be 75# and the dually rear tires cold psi should be 60#. Now the 5# difference in the front tires seems prettyminor but the 20# on the rears Is significant. My gut tells me to follow the truck manufacturers sticker.Recommendations?
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Follow the truck manufacturer's door jamb sticker. Your truck is a dually and the lower pressures for the rear tires are common because there are 4 tires to carry the load.
My 2016 F350's recommended pressures are 75 psi front and 65 psi rear.
-- Edited by RonC on Saturday 8th of October 2016 06:33:04 PM
-- Edited by RonC on Saturday 8th of October 2016 06:33:53 PM
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Ron and Janice
2016 Ford F350, King Ranch, DRW, 4x4, CC, 6.7 PS Diesel, remote control air lift system
2017 Durango Gold 381REF, Lambright furniture, MCD shades, morRYDE IS, 8K Disc brakes, GY G114 LR H Tires, 27,320 lbs CGVW
So I am a tad confused on the tire pressure for my 2014 F 450. According to the "tires" the cold psi should be 80#. On the door jamb of the truck it estates front tires cold psi should be 75# and the dually rear tires cold psi should be 60#. Now the 5# difference in the front tires seems prettyminor but the 20# on the rears Is significant. My gut tells me to follow the truck manufacturers sticker.Recommendations?
The rating of 80 psi on the tires is most likely the maximum inflation pressure (which will give you the maximum load the tire can potentially carry). Remember that tires are rated differently when used in a dual application or a single ... you'll find that info right on the side of the tire near where you saw the 80 psi. Tires are used in many different applications, so the numbers on the side of the tire are generic and not for your specific application. The manufacturer takes those tires and using the charts that Cummins12V98 referenced and applies them to your specific vehicle and it's ratings. For that reason, use the manufacturer's recommendation because it factors in other things besides just the tires ... things like, axle ratings, bearing loads, spring rates, ride quality, tire life, etc. Yes, you can inflate to maximum on the tires, but this generally just gives you a harsher ride but no additional capacity. My rear axle is rated for 9,650 lbs. The recommended inflation pressure is 65 psi (the tires can carry 2,950 lbs at 80 psi in a dual application) which implies that with 4 of them pumped up to 80 psi, they can carry 11,800 lbs. HOWEVER, the rear axle is only rated for 9,650 lbs, so Ford uses the charts and lowers the recommended pressure to 65 psi, which matches the tires capacity to the axles rating. The front tires (which is a single tire application) is rated to carry 3,195 lbs @ 80 psi. This would imply that I could carry 6,390 lbs on the front axle, but the front axle is rated at 5,940 lbs. This acccounts for why Ford lowered the front tire pressure to 75 psi.
Yes you can increase tire pressure up to the maximum and possibly get better tire mileage (or not) but you will definitely get a harsher ride.
I suggest that you don't second guess the manufacturer's engineers, they really do know what they are doing, and they want you to get the best ride, the best wear and the rated capacity, which will be the outcome of following their recommendations.
-- Edited by RonC on Sunday 9th of October 2016 08:09:29 AM
-- Edited by RonC on Sunday 9th of October 2016 08:10:28 AM
-- Edited by RonC on Sunday 9th of October 2016 08:11:34 AM
-- Edited by RonC on Sunday 9th of October 2016 08:12:15 AM
-- Edited by RonC on Monday 10th of October 2016 03:09:50 PM
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Ron and Janice
2016 Ford F350, King Ranch, DRW, 4x4, CC, 6.7 PS Diesel, remote control air lift system
2017 Durango Gold 381REF, Lambright furniture, MCD shades, morRYDE IS, 8K Disc brakes, GY G114 LR H Tires, 27,320 lbs CGVW
I would highly recommend running the tires at the recommended psi that the vehicle manufacture states. As was mentioned tires carry a specific MAX psi pressure/load, but that particular size can fit various applications. The vehicle manufacture along with the tire manufacture decide what pressure works best for each vehicle.
The reason for the disparity on the pressures front to rear are simple, in a single application the carrying capacity dictates it load carrying capacity, in a dual the same but the carrying capacity of each in a dual application is reduced by 10%.
Keep in mind over inflating can lead to irregular wear, a harsher ride, a reduction in the "footprint" (or amount of rubber on the road). Think about it in these terms, what stops you vehicle?
There are a lot of so called experts alive and well out there who may have had some luck in the past but at the end of the day it's hard to argue with the vehicles manufacture.
I spent over 35 years in the tire industry and won't say I'm an expert, knowledgeable and experienced, but not an expert.
Rickl I assume you being in the tire industry are an advocate for using the load inflation guide if one knows what the load is on the tires? Since the MFG will give psi based on max capacity and not everyone runs max capacity.
Rickl I assume you being in the tire industry are an advocate for using the load inflation guide if one knows what the load is on the tires? Since the MFG will give psi based on max capacity and not everyone runs max capacity.
Absolutely I agree. But there are issues with that. First just to be clear I don't believe in running the tire over the manufactures recommendations. Second, a number of years ago trailer tire manufactures moved away from using the load charts and recommended max pressure because people were NOT adjusting the pressures as needed. And really the same goes for vehicles. Here is the kaveat however IF, and I mean IF, you will check and adjust your tires on an ongoing basis utilizing the load chart is a great way to go. If you are not one of those that can be consistent in checking the pressure AND knowing the exact load then stay at the manufactures recommendations.
If you look at the load chart 1 lb as you get lower in pressure can mean a substantial difference in weight carrying capacity. That lower pressure can result in tire jounce which rapidly increase heat. Think of flexing a steel coat hanger. If you haven't flexed one try it and feel the heat at the bend.
