Grit dog wrote:
SJ-Chris wrote:
LT225/75R16C 121/120R: The reason I use them is because they have 2000lbs of extra carrying capacity at 80psi. Gives me peace of mind. I believe they are safer. Safety is important to me.
Personally, I see no downside in having extra weight carrying capacity. In my opinion, they are less likely to blow. If one does go flat, the remaining one that is temporarily carrying the full load will be less likely to also blow.
Note: You should never intentionally overload your rear axle.
Safe travels!
Chris
No downside other than availability and price. Sure, if one needs the added capacity, great. But based on your last statement, that's not likely unless one is actually overloading the "real" axle capacities (aka the 10-11klb range) of the vehicle.
And if the extra capacity is needed, barring some obscure tire clearance issue on the RV, there are other options that are of similar or same capacity and not an obscure Euro tire size (albeit not as obscure as years past with the amount of Sprinter type vans running around.
Overkill is fine, it's one person's own money vs peace of mind I suppose. Just pointing out the (not obvious to everyone) differences and costs/challenges for little to no real world gain.
I hardly consider it overkill...
I went through ZERO hoops/effort to buy tires that each have an extra 500lb carrying capacity. They aren't Euro tire size. I believe they are from South Korea or Japan. They have similar Commercial load rated tires (121/120 load rating) at Big-O tires, Firestone, America's Tires, Discount Tires, CostCo, etc. AKA just about everywhere. I think the ones I got were $15 more per tire when I bought them compared to a corresponding E-rated load tire.
Here's why it isn't Overkill...
225/75R16C rated duallies in the rear have a 80psi carrying capacity of 4 x 2975 = 11,900lbs
whereas 225/75R16E E-rated duallies in the rear have a 80psi carrying capacity of 4 x 2470 = 9,880lbs
Let's assume your rear axle was at a maximum weight of 9,600lbs. Would you rather have the E-rated tires that have only a 280lb margin, or the C-rated tires that have a 2,300lb margin? I would rather have the C-rated tires. 280lbs is 2.8% of buffer/margin. 2300lbs is 23% of buffer/margin. 10x more buffer/margin. I consider that a significant gain and worthwile (at least for me).
Personally, I don't feel comfortable with potentially only 2.8% of buffer/margin.
Next question: Does the typical RVer check your tire pressure EVERY DAY before they drive? I'm guessing 99% of people do not. (I have a TPMS so I can see always). What happens to these margins when the tires are actually at 75psi instead of 80psi? Or 70psi? Or 65psi? Answer: It spells trouble for E-rated tires, but the Commercial load rated tires still have plenty of carrying capacity buffer.
Side note: Nobody should ever overload their rear axle, even with tires that can handle a heavier load. What % of RV owners know (weighed at a scale) how much their rear axle weight is? Probably less than 5%.
All good. Just my opinion. I'll pay a tiny bit more for what I perceive to be a large extra margin for the potential safety of family and friends. Have yet to have a blowout on my two 30' Class C RVs that have these Commercial load rated tires on them. Everyone is free to choose whatever tires they want for their RV.
Safe Travels!
Chris
