Old Dodge SMB Tire Pressures

[hippievan]

The Sportsmobile recommended tire pressures are no longer visible on the doorplate of our new 2002 Dodge B3500 RB-50 5.9L. Anyone know what those pressures might have been? Wanting to know more for their front/back pressure ratio more than anything.

SMB-installed weight would be propane furnace, Starcool A/C, gas 2.8K generator, elec water heater, ladder. The standard chrome wheels and tires of the day. Has BFGoodrich A/T highway tires.

Sorry no picture as the van is at the local shop getting all the preventive maintenance up to date and front end suspension work. KYB shocks replaced at 85K; now at 105. Spongy like trampoline, especially potholes and speed bumps.

Thanks for any info,

Mike

[campism]

My '94 B350 is not an SMB but is a highroof (ex-wheelchair) van with a gutted interior that will eventually be built out for camping with a functional but not overdone interior. Door sticker lists front at 45 and rear at 80. I'm surprised the F/R varies by as much as it does, but this van had an externally-mounted lift on the rear so that would have been a lot of metal hanging off the back. Don't know how different build configurations on the same basic van body might affect the recommended pressures. Hope this helps.

[REF]

Really depends on current tire specs more than the old placard. D or E rated? Check the sidewall for max pressure. For example, most here will tell you they’ve switched over from original SMB spec’d D tires to a heavier E rated tire that run higher psi, so the door placard wouldn’t be relevant, most E tires are 65psi max. I run 315 E rated GY Duratracs at F-55/R-60 for general highway and towing and air down when going offroad.

[86Scotty]

^^^ Yep. Weigh the rig, follow what's on the sidewall balanced with your load. I run 55-60 with E-rated tires for maximum comfort and handling in every heavy van I've had. I would recommend E rated tires for a built out van no matter what you have now. They build less heat than any passenger tires and that is what you want for safety and longevity.

[Orv]

The stiffer sidewalls on heavy-duty tires also improve handling on vans. It's pretty noticeable. But any SMB is going to be exceeding the load rating for passenger car tires.

[hippievan]

Thanks for all the comments above. The van is still with the mechanic, but I do know the tires are load E max 80 psi. And the van weighs 7040 pounds total. So it sounds save to run 55F / 60R until I get tire specs, front/back weights, and use that table on some thread around here for minimum front/back tire pressures based on front/back weights. Wasn't planning to go that route but ya'll talked me into it.