Tires

[sgt1577]

I’m about to put new tires on and was looking for a little feedback! Anyone using
General Grabber tires? Specifically the 225/75R16C that are commercial with a little higher load rating.

Thanks!

[kwftlaud]

I bought these last month for $116 each from Walmart.
they are Commercial tires so they have a higher load rating than normal RV tires.
I haven't taken them on a trip yet, but, they seem OK to me
kip

https://www.walmart.com/ip/Atturo-CV...Tire/411359058

[SJ-Chris]

What RV make/model are you putting these tires on? What is the max weight recommended by the manufacturer? (you can find this on the factory sticker on the driver side door jam)


Many ~30' Class C RVs (for example) ask for an E Load rating. But if you do the calculations you will find that there is very little "buffer" in the max RV axle weight (specifically the rear axle) and the max load carrying capacity. The problem gets worse if the tires are not properly inflated. For my ~30' Class C RVs I have been using Commercial rated tires which each have ~500lbs of extra carrying capacity (~2000lbs extra on the rear axle). This gives me better piece of mind. Less chance for a blowout.


I have been buying from Big-O tires and can usually find Commercial tires of that size for ~$120 each.


I also have a smaller 23' Class C RV. The rear axle max load is a fair amount less than my 30' RVs. For the 23' RV I am perfectly fine with using the E Load rated tires.


One thing to keep in mind...On most RVs, the tires AGE out rather than WEAR out. Most people do not put 40k, 50k, 60k on their tires on their RV. After 5-6 years you will likely want to replace your tires (regardless of miles) as they will start to show signs of cracking/etc. So unless you realistically plan on putting 10k miles or more per year on your RV, finding tires with high mileage guarantees might not be worth the extra money.


Just my 2 cents.


Good luck!
Chris

[sgt1577]

Thanks for the info! I have a ‘17 Fleetwood Jamboree that’s at 32’ long! Probably at the max weight limit when it left the factory! The Michelins that are on it are nowhere close to worn out. I am changing them due to age-I do NOT want to experience a blow out!

[Ron Dittmer]

Originally Posted by sgt1577

Thanks for the info! I have a ‘17 Fleetwood Jamboree that’s at 32’ long! Probably at the max weight limit when it left the factory! The Michelins that are on it are nowhere close to worn out. I am changing them due to age-I do NOT want to experience a blow out!

Be sure to get the commercial grade "E" rated tires that handle an extra 550 pounds per tire. That is an extra 2100 pounds of capacity on your rear axle at 83 to 90 psi pending the brand of tire. The tires are not that common. Check out www.tirerack.com to find some choices. The Michelin Agilis CrossClimate-II is one but there are other brands as well.

[twinboat]

Originally Posted by Ron Dittmer

Be sure to get the commercial grade "E" rated tires that handle an extra 550 pounds per tire. That is an extra 2100 pounds of capacity on your rear axle at 83 to 90 psi pending the brand of tire. The tires are not that common. Check out www.tirerack.com to find some choices. The Michelin Agilis CrossClimate-II is one but there are other brands as well.

You can't just assume the rig can carry another ton of weight just because you changed tires.

The rear axle, springs, frame and brakes all come into play with added weight.

A 32 foot long E450 is most likely at its max as built.

[Ron Dittmer]

Originally Posted by twinboat

You can't just assume the rig can carry another ton of weight just because you changed tires.

The rear axle, springs, frame and brakes all come into play with added weight.

A 32 foot long E450 is most likely at its max as built.

Without changing anything else on his rig including his loading habits, he can greatly reduce his primary threat of "Tire Blowouts" by upgrading his standard "E" rated tires to commercial grade versions. 32 footers with multiple slide-outs, tire blowouts will surely be his greatest threat.

I don't endorse over-loading the motorhome, only stating the most serious risk of danger and/or damage on such a rig.

[SJ-Chris]

Originally Posted by twinboat

You can't just assume the rig can carry another ton of weight just because you changed tires.

The rear axle, springs, frame and brakes all come into play with added weight.

A 32 foot long E450 is most likely at its max as built.

An RV should never be overloaded beyond the max recommended weight (...you can check the sticker on the driver side door frame). That being said...30'+ Class Cs are usually near that max weight rating when loaded up AND the recommended tires per the sticker have very little excess weight carrying capacity (very little buffer). I'm honestly surprised that manufacturers (or the governing entities) allow it. Load carrying capacity is also highly dependent on having proper PSI on your tires and many RVers are not as diligent as they should be about this (...I recommend a TPMS). So....regarding tires on 30'+ Class C RVs I highly recommend using Commercial rated tires (Important: "C" load rating are NOT commercial...you need Commercial rated 121 load capacity tires). These have ~500lbs of extra carry capacity EACH as compared to the recommended E-load rated (115) tires. That equates to 2000lbs of excess buffer.


Again, that doesn't mean you should add 2000lbs of extra load! It just means that all else being equal your Commercial rated tires will have a much easier time carrying your RV/load down the road. This will help compensate for non-ideal PSI in your tires, or pot holes, or anything else that might put excess strain on your tires. It should help reduce the possibility of a blowout.


In my experience, the extra cost per tire from an E-load vs Commercial tire is ~$15-30/tire. Well worth it.


Also, the front axle carries less load and even with E-load rated tires there is a reasonable buffer in the carrying capacity. It would be reasonable to have Commercial load tires on the rear (dually) and E-load rated tires on the front if you really wanted. Personally, I just put Commercial load rated tires on all 7 (which includes the spare).


Safe travels!
Chris

[twinboat]

The most common cause of tire blowouts is under inflation. Doesn't mater what load range they are.

[SJ-Chris]

Originally Posted by twinboat

The most common cause of tire blowouts is under inflation. Doesn't mater what load range they are.

I'm no tire expert, but I assume tires that are overloaded (combination of psi and weight) have a higher chance of blowing out. The Commercial load rated tires, at the same psi as the E-load tires, will be able to carry more load. Therefore, they would have less chance of blowing out as compared to E-load rated tires.

[twinboat]

Originally Posted by SJ-Chris

I'm no tire expert, but I assume tires that are overloaded (combination of psi and weight) have a higher chance of blowing out. The Commercial load rated tires, at the same psi as the E-load tires, will be able to carry more load. Therefore, they would have less chance of blowing out as compared to E-load rated tires.

They may have a higher chance of failure, being overloaded compared to proper loading and pressures, but you should not be in that situation with factory rated tires.

Under inflation is still the most common cause of tire failure, look it up.

[sgt1577]

Thanks for all the great info! The tires that are going on today are the ones I mentioned in the OP. They are load range E but also the commercial version that has the higher load rating. The Michelins that are coming off still have great tread left after almost 30K miles! They are 6 years old and have to go. 3000 mile ride home and I do not want to have tire trouble! Extra benefit by getting them here in Portland is that I dodge the NYS sales tax!

[THenne1713]

<<Be sure to get the commercial grade "E" rated tires that handle an extra 550 pounds per tire. That is an extra 2100 pounds of capacity on your rear axle at 83 to 90 psi pending the brand of tire.>>
It is rather CONFUSING when talking LT Tires vs Euro Metric Commercial tire. In the (LT225/75R16E) the E is a PLY RATING, (E=10 PLY RATED), even though maybe One steel ply or 7 PLYS, where the (Euro-Metric 225/75R16C, 121/120 Load, 83psi MAX), the "C" is "Commercial", whereas in the old LT Tires, a C1 or C2 (35 or 50 PSA Max), the C1 OR C2 was a 6-PLY RATED.

[SJ-Chris]

Originally Posted by twinboat

They may have a higher chance of failure, being overloaded compared to proper loading and pressures, but you should not be in that situation with factory rated tires.

Under inflation is still the most common cause of tire failure, look it up.

An RV should never be overloaded compared to the maximum allowed weight for the rig.


AT THE SAME RV LOAD/WEIGHT, Commercial rated tires will have an easier time carrying the rig (and therefore, less risk of a blowout) compared to E-load rated tires at the same PSI. Commercial rated tires are able to carry about 20% more than E-load rated tires.

An under inflated (say 65psi) Commercial rated tire can carry more weight than an under inflated (say 65psi) E-load rated tire. In my mind, that means the Commercial rated tire should be less likely to have a blowout in that scenario.

It's kind of like saying, What lumber can hold up this weight better? A 4x4 support beam or a 4x6 support beam.


I believe adding a simple tire pressure monitoring system to any RV without one is important, and can be done for less than $100. It is not always easy to notice when your rear inner dually tire is flat by a casual visual inspection. But when your TPMS says it is flat you will be glad you have it so that you either don't start driving, or if driving you immediately slow down and pull over to avoid a high speed blowout.


Of course everyone is welcome to use whatever tires they want.

Safe travels!
Chris