Factory Rim Pressure Limit April 28, 2019, 03:25:46 pm My 1990 27' LD has a 65lb. psi max stamp on the factory 16" rims. The door jam sticker recommends 65 lb.s. When I replaced the original factory spare (29 years old!) I noticed it was rated at 65lb.s maximum pressure. All my new tires are rated 80lb.s maximum pressure. I am running metal valve stems. My question: many people here in the Arizona desert are all about running max tire pressure rating to keep temps low.. Is 80lb.s psi too much for that era of rim?
Re: Factory Rim Pressure Limit Reply #1 – April 28, 2019, 04:38:45 pm Quote from: Jagerbeast - April 28, 2019, 03:25:46 pmMy 1990 27' LD has a 65lb. psi max stamp on the factory 16" rims. The door jam sticker recommends 65 lb.s. When I replaced the original factory spare (29 years old!) I noticed it was rated at 65lb.s maximum pressure. All my new tires are rated 80lb.s maximum pressure. I am running metal valve stems. My question: many people here in the Arizona desert are all about running max tire pressure rating to keep temps low.. Is 80lbs psi too much for that era of rim?How much air pressure is too much is an engineering question that none us are qualified to answer.That said, your MB tires probably always been at or above 65-psi, you might give Steve, at LD, a call for a better answer .Larry 2 Likes
Re: Factory Rim Pressure Limit Reply #2 – April 28, 2019, 05:13:59 pm The tires and valves could certainly handle more, but you said the RIMS have a 65 PSI limit. That means they may fail under higher pressures. That would be a rather dramatic event, I think. Like Larry said, the factory may know, but I would suggest asking the rim manufacturer if you can determine who they are.If you REALLY want a higher pressure, you might be able to replace the rims with something with a higher pressure rating, but consider this first. The tires and their pressure is part of your suspension system. When you use too high a pressure, you generate a harder impact from every bump in the road directly to the axle, bearings, springs and shocks, and indirectly to the steering components and the coach and its contents. Personally, I would not do it.Ken F in OR 1 Likes
Re: Factory Rim Pressure Limit Reply #3 – April 28, 2019, 05:27:47 pm Quote from: Kenneth Fears - April 28, 2019, 05:13:59 pmIf you REALLY want a higher pressure, you might be able to replace the rims with something with a higher pressure rating, but consider this first. The tires and their pressure is part of your suspension system. When you use too high a pressure, you generate a harder impact from every bump in the road directly to the axle, bearings, springs and shocks, and indirectly to the steering components and the coach and its contents. Personally, I would not do it.One consideration is how much the rig weights and what the tire manufacturer's recommended pressure is for that weight.I'm surprised the rear tires are not in the 70-lbs range. Since it's a E350, the rear axle load may be light enough not to require more pressure. Have you weight the rig?If the tires require more than 65-psi cold, updating the wheels to a newer design, capable of the higher pressure is recommended. As long as the wheels are properly size and backspaced, it should not have any negative effects .Running excessively high pressures will wear the center of the tires more quickly and provide a rougher ride, I would run the recommend pressure.Our LD's tires are run at 5-psi over the recommended pressure, to allow for leakage and to reduce having to often add air.Larry 2 Likes
Re: Factory Rim Pressure Limit Reply #4 – April 28, 2019, 08:50:11 pm Could the 65 psi on the rim represent a maximum inflation pressure for seating a tire bead?My recommendation is that you call the manufacturer of the tire you have after weighing your vehicle and ask to talk with their engineering or technical department for their suggestion. The manufacturer is the ideal source of information for all tire application related questions. 1 Likes
Re: Factory Rim Pressure Limit Reply #5 – April 29, 2019, 12:49:13 am I second talking to the tire manufacturer. When we got new tires (and were planning a 10 hr driving one way trip), I got the manufacturing information on what the PSI should be under different loads and conditions. It came as a large table.That way I know (rather than guessing) how our tires should be inflated. 1 Likes