I wanted to get on the phone early this morning and figure out our tire situation. Linda & I agreed that there would never be a good time financially to upgrade our tires and wheels.
And we've had so many friends with large trailers (and some not so large) that have had blowouts with the same tires we have - the Goodyear G614 LT235/85R16 Load Range G tires. In fact, Mark & Dale Bruss who I linked to yesterday, had a blowout at the end of August with the same tires.
Like us, they were going to wait to upgrade until next year. Well, that changed quickly. So, the safety factor and peace of mind are just too important to put the decision off any longer.
A quick tire refresher. As Mark says, "Your tires are the foundation of your RV. Everything is supported on your tires. The selection, monitoring, and care of your tires is crucial to the safety of your RV experience."
Reading A Tire
Let's look at the Goodyear G614s we have - LT235/85R16 Load Range G.
LT = Light Truck (For most car tires the numbers are preceded by a "P" for passenger)
235 = The width of the tire in millimeters (To convert to inches divide by 25.4); 235 mm / 25.4 = 9.25 inches)
85 = The aspect ratio; This is the ratio of sidewall height to width; So this tire's sidewall height is 85% of 235 mm or 199.75 mm; Converted to inches that would be 199.75 mm / 25.4 = 7.86 inches (9.25 inches X 85% = 7.86 inches); Keep in mind that is one sidewall from the ground to the tire wheel/rim - so there is another 7.86 inches from the top of the wheel to the top of the tire; High performance tires, which we don't need for RVs, have low aspect ratios because the shorter the sidewall, the better the tire performs in turns at higher speeds
R = Radial (a B would indicate bias tire construction, but we're dealing with radials on full-timing RVs)
16 = Wheel diameter in inches; So this tire requires a wheel/rim of 16 inches
Load Range G = maximum load of 3,750 pounds at the maximum pressure of 110 psi for this tire; Although the tires have load range codes, they also indicate the exact maximum loads and pressures on the sidewall
Note: Load ranges are indicated by letters on Truck tires (the higher the letter, the higher the load capacity). See Truck Tire Load Range Chart Load ranges for Passenger tires are indicated by numbers with higher numbers having higher capacities.
The reason we want to change tires is because we don't have enough cushion on the weight capacities of our current tires. In a perfect world with unlimited cash, we would change our 7,000 pound axles to 8,000 pound axles and change the tires and wheels and everything else necessary for that change.
However, we have been told by the professional RV weighers (we have weighed twice) that we are probably okay on the axles, but really should change the tires since we are overweight on individual tire positions. That is more of an issue with the design of our fifth wheel than anything. We have three slides on our left side with most of our weight concentrated there. We are talking "built-in" weight, not weight we can shift.
So what are the considerations in changing tires? All experts say you should have the same size tires with the same capacities. So, it's not just as easy as getting better tires for our left side. Also, there are no tires we can find that have higher capacities and fit on 16-inch wheels. The wheels have to have the same or higher capacities as the tires. High capacity tires on lower capacity wheels doesn't help. :)
Therefore, to upgrade and get the weight capacity we want, we had to research changing tires and wheels. So what did we have to consider for that? I went through tire websites, and RV websites and forums.
If the new tire diameters are too high, we might have clearance issues between the trailer and between the tires themselves. If the tires are too wide, then we might have fender clearance issues. If the wheels don't fit on our current hubs, we would have to change hubs, brakes, and other components.
So the goal was to find tires with a higher capacity and similar size that fit on wheels that were compatible with the current hubs. Everything I could find pointed to 17.5 inch wheels with H-rated tires with a load capacity of 4,805 pounds per tire.
I narrowed down the choices, but was still confused enough to need help before pulling the trigger. It's too expensive a decision to make a mistake and buy incompatible tires/wheels.
Fortunately, that's when I discovered Mark & Dale had just gone through the process and had the exact same tires and axles we have. After reading his New Sized Tires page, I knew he had done the research and come to the same conclusions I had. Still, I needed reassurance so I called him this morning.
I got the reassurance I needed. We're also going with the 17.5" X 6.75" 865 Aluminum Hi-Spec Series 3 Trailer Wheel with 4,850 pound capacity from Trailer Tire & Wheel Supermarket. In addition to Mark and the folks from Weigh-It Portable RV Scales, I've gotten other suggestions to use this company. These wheels will fit on our hubs and axles without modification.
And for the same reasons as Mark, we are going with the Goodyear Unisteel G114 LHT 215/75R17.5 H-Rated tires. These tires are actually a little narrower (215 vs 235 mm, about 8.5 inches vs 9.25 inches) and .2 inches smaller in diameter so there are no clearance issues to worry about. Because of the narrower width and lower aspect ratio, the sidewalls are shorter and offset the 1 1/2 inch larger wheel. So it's a smaller tire with greater strength and better performance in turns. However, the "contact patch" (the amount of tire touching the pavement based on width) is about 3/4 of an inch less.
Note: There is a G114 LHT 235/75R17.5. So why didn't we go with that wider tire that actually has even more capacity? Well, a couple of reasons. First, it is well over an inch more in diameter than what we currently have so there are compatibility issues. Second, it has a speed rating of 62 mph whereas the smaller tire has a speed rating of 75 mph. Like Mark, we don't intend to go 75 mph, but we like the extra cushion. In fact, almost all the other tires requiring 17.5 inch wheels have the lower speed rating. Lots of folks like the Michelins in Mark's tire comparison table except for the speed rating. Oh, the G114s also come in an F Load Range in the 215/75R17.5 size - gotta be careful to not order that lower capacity tire as that's what we were quoted by one dealer. :)
I called various Goodyear stores on our path to Arizona to get pricing on the tires. They either couldn't find the tires or they priced them between $370 and $390 each. One store came down to $349. And that didn't include sales tax or labor and was going to end up around $430 per tire.
I called Trailer Tire & Wheel Supermarket since their website says they can package the tires with the wheels. I just assumed their price and the shipping would be too much. I was wrong. :)
Their price was $287 per tire. And they will mount the tires on the wheels for free and balance them for $6. The written quote for four tires/wheels was for $2,230 including shipping to Buckskin Auto up the road. All I'll have to do is have them mounted.
We're hoping to place the order and get them on the truck Monday. :)
The Rest of Our Day
Whew! With that decision finally made, we had to pick up some toner for our printer and run a couple other errands. The main goal was to fill the truck up with diesel.
With our ten cents off using our City Market card, we filled both tanks on the truck for $130 at $3.29 per gallon. The last time we filled up at the end of June it was $4.89 per gallon. Wow!
On the way back, we stopped at Buckskin. I wanted to make sure they would accept the tires/wheels if I shipped them there. It was fine.
I also made an appointment for next week to get the truck serviced and the tires on the truck rotated. The tires are showing some wear and they haven't yet been rotated. We had budgeted for a service in October, but I guess early November will do. :)
Speaking of budgets, I spent the rest of the afternoon and early evening doing the October Financials. The entry is below this one. Another thing off my list. :)
Linda is on a beading frenzy as she has a few orders to fill. And she made her Taco Soup recipe in the crockpot for dinner. Always good on a chilly night. :)
And that was about it for our day. We may or may not be more exciting tomorrow. :)