โJul-12-2014 10:00 PM
โJul-15-2014 04:53 PM
wintersun wrote:
Big mistake to go by the tire manufacturers' charts. Use the vehicle manufacturer's recommended pressure as that is what they have designed the suspension for and it is vehicle specific.
Use the charts and the tires will be underinflated and tread life will be shortened and handling will be worse.
โJul-15-2014 03:07 PM
โJul-14-2014 04:48 AM
โJul-14-2014 01:50 AM
Grandpere wrote:NC Hauler wrote:past-MIdirector wrote:
Need to look at the load range on the replacement tires. Most RV replacement tires are one or two load ranges high with a higher max. pressure then what was originally put on. I was taught many moons ago that to be safe air tires to 10% of what the max. pressure is on the tire. This has worked for 40 years now.
Well, I'll admit I've never done that, I've alway's aired to max sidewall rated psi...never added an extra 10% which would be loading a Michelin "E" rated RIBS to 88# instead of 80 and airing my GY G614's to 121 psi instead of the recommended 110psi...one could do that, but again, I've been towing since 75, (and some before that), and also never had an issue... and thats worked for me for almost 40 years also...
My experience has seen most newer RV's with tires on them that are "just close" enough to cover axle rating...as little as the manufacturer can get away with and cut corners on cost. It's rare that I've seen a "G" rated tire where an "E" rated tire would have worked...it's very, very rare.
What he meant was 10% under the maximum pressure, not 10% over the maximum pressure. This was to allow the old bias ply tires to expand pressure from heat and keep them within a safe operating pressure. I also run 100 pounds in my tires that have a max rating of 110 pounds, my dad sold Goodyear & Atlas tires in the 60s and 70s and this is what I was taught. How this theory holds up today with radials I do not know, all I know for sure is that my dad still holds to this theory and it has worked well so I am continuing the tradition. Also, in the old school days, putting the next size bigger tire was also standard practice as auto manufacturers are notorious for putting marginal tires on their vehicles, it looks good on some draftsman's drawings, but in the real world, it hold no water--e.g. the tire debacle with Ford Explorers a few years ago, too small a tire for the weight of the vehicle caused lots of problems. That is why I changed my 8r19.5s for 245x70r19.5s, slightly larger in diameter, much wider foot print, and my mh handles much better. When my van gets new tires this winter, I will jump it 2 sizes 215x70r15 to 235x75r15 they 215s are toooooo small a tire for the weight of the van and at max pressure the sides are still wearing out faster than the centers.
โJul-13-2014 08:26 PM
NC Hauler wrote:past-MIdirector wrote:
Need to look at the load range on the replacement tires. Most RV replacement tires are one or two load ranges high with a higher max. pressure then what was originally put on. I was taught many moons ago that to be safe air tires to 10% of what the max. pressure is on the tire. This has worked for 40 years now.
Well, I'll admit I've never done that, I've alway's aired to max sidewall rated psi...never added an extra 10% which would be loading a Michelin "E" rated RIBS to 88# instead of 80 and airing my GY G614's to 121 psi instead of the recommended 110psi...one could do that, but again, I've been towing since 75, (and some before that), and also never had an issue... and thats worked for me for almost 40 years also...
My experience has seen most newer RV's with tires on them that are "just close" enough to cover axle rating...as little as the manufacturer can get away with and cut corners on cost. It's rare that I've seen a "G" rated tire where an "E" rated tire would have worked...it's very, very rare.
โJul-13-2014 03:00 PM
Cummins12V98 wrote:NC Hauler wrote:Cummins12V98 wrote:
Jim your HR came with E tires correct? They recommended max pressure at 80 psi correct? The G tire Carries the same load as the E at the same pressure. So to say HR wants you to run 110 psi on your G tires does not sound right.
Run what you want it's up to you but talk to GY tech they will tell you that you can use the charts for proper inflation based on load when up sizing the load rating.
My 5er has a GVW of 16,950 with 7,000# rated axles...My 5er came with GY G614's..... 110 psi....that's what is listed on the placard on the 5er and that is also what Goodyear recommended.
OK. I saw something about you having E tires must have been on another RV.
โJul-13-2014 01:47 PM
NC Hauler wrote:Cummins12V98 wrote:
Jim your HR came with E tires correct? They recommended max pressure at 80 psi correct? The G tire Carries the same load as the E at the same pressure. So to say HR wants you to run 110 psi on your G tires does not sound right.
Run what you want it's up to you but talk to GY tech they will tell you that you can use the charts for proper inflation based on load when up sizing the load rating.
My 5er has a GVW of 16,950 with 7,000# rated axles...My 5er came with GY G614's..... 110 psi....that's what is listed on the placard on the 5er and that is also what Goodyear recommended.
โJul-13-2014 01:00 PM
โJul-13-2014 12:01 PM
Cummins12V98 wrote:
Jim your HR came with E tires correct? They recommended max pressure at 80 psi correct? The G tire Carries the same load as the E at the same pressure. So to say HR wants you to run 110 psi on your G tires does not sound right.
Run what you want it's up to you but talk to GY tech they will tell you that you can use the charts for proper inflation based on load when up sizing the load rating.
โJul-13-2014 11:08 AM
โJul-13-2014 10:36 AM
Cummins12V98 wrote:
Jim your HR came with E tires correct? They recommended max pressure at 80 psi correct? The G tire Carries the same load as the E at the same pressure. So to say HR wants you to run 110 psi on your G tires does not sound right.
Run what you want it's up to you but talk to GY tech they will tell you that you can use the charts for proper inflation based on load when up sizing the load rating.
โJul-13-2014 10:27 AM
โJul-13-2014 09:08 AM
blt2ski wrote:
Jim,
I do this for the trucks, trailers I run at max sidewall pressures. My trucks, especially the rears. The 70 or 75 series tires we seem to be getting on newer rigs today is more susceptible to the middle wearing out if you run max psi and then run the rig empty for long periods say commuting. A pizza cutter tire, ie an 85 series this does not seem to be an issue. I was able to run 70 psi in a 235-85-16 empty on a pickup and get full tire width contact, where as a 245-75-16 was in the 55-60 range. Both tires have the same total wt at psi etc per a tire chart.
My old dually, I only need 50-55 when empty, then again, it only had 3-3200 lbs on it. Single tired rigs seem to have 2100-2400 ont he RA, so again, no need to have full psi. Rides really rough too.
The visual with water, dust etc seems to give me a pretty good clue if I have too much psi in the tires. I have never weighed ea tire. I do go thru the DOT scales to see how I am doing on axel wts at times. but otherwise, no need to weigh, as ea trip will be slightly different per say.
marty
โJul-13-2014 09:04 AM