A visual always helps. In these pictures you can see the circumferential raised lips, or beads, on a typical light-truck wheel which are often called the “safety bead”. They help the tire stay on the wheel. The first photo below shows a relatively new, 17 x 8-inch TRD Tundra wheel, but they are all similar. The safety bead ring is inboard approximately one inch from the actual tire bead seat.
TRD 17 inch Tundra Rock Warrior wheel safety bead rings.
Below is another example, a very well used 16 x 7.5-inch TRD FJ Cruiser wheel, which has had several sets of tires mounted.
TRD FJ Cruiser 16 x 7.5-inch wheel with circumferential safety bead rings.
I received the email below asking for input, and with the reader’s permission, decided it would be nice to respond to his question on the blog and share with everyone.
Do you have a question for RoadTraveler.net? When you do, send an email, maybe RoadTraveler can help.
Question:
I was wondering if I could pick your brain for a minute. I just bought another F350 CC today. 97 Powerstroke with built E4OD. It is going to need rubber soonish, and I have also recently bought a 2700 lb slide in camper. I am looking for a load range E 315-75 R16. All i have found so far is the Toyo MT. I am fine with those, aside from cost vs wear ratio. Any other hats you could throw in the ring?
Much appreciated, Red Thies
Answer:.
I love the old, first generation 7.3L Power Strokes, sounds like you found a good one. As you know, you have a substantial load with that slide-in camper. I assume you desire a load-range E 315/75R16 because you want the added capacity of over the typical load-range D, and possibly the added stiffness to reduce sidewall flex and heat.
Does the camper weigh 2,700 pounds dry or is that the gross-vehicle-weight-rating (GVWR)? My guess is that with the weight of that camper you will be very close to the maximum capacity of two typical 315/75R16Ds, which is 3,195 pounds each at 50-PSI. Depending on how you set-up the F350, you might have close of 3,000-pounds riding on the rear axle (I do) when you are wet & empty before you install the camper. Using these estimates, you would have about 690-pounds of total rear axle tire payload remaining.
I’m generally a fan of the Toyo M/T because it’s a high-quality, rugged tire that balances well and rolls nicely down the road. However, you raise a very valid point; value. The Toyo M/T is generally pretty expensive, and depending on the application, wear is not always fantastic. I also know a few people who didn’t get great mileage out of their Toyo A/Ts either. As the saying goes, your-mileage-may-vary, there are always others who can share they get great wear out of Toyos. Depends. Do you want a mud-terrain tire? Diesels can be hard on tires, and so can maximum loads, therefore starting with a tire that has a spotty reputation for wear is a big gamble.
The GoodYear DuraTrac LT315/75R16 is a load-range E tire, rated for 3,860-pounds each at 65 psi, a very healthy increase in capacity. But like the Toyo M/T, some seem to get great wear out of the DuraTrac while others receive a very short life. I like the appearance of the tread, but it hasn’t been able to lure me away from the Dick Cepek F-C II.
The Firestone Destination M/T is a load-range E in 315/75, and comes with a whopping 20/32″ of tread. The Firestone Destination A/T is also a load-range E, but is a very conservative 5-rib all-terrain tread design.
Several weeks ago I posted about purchasing a set of OE 17-inch TRD wheels which included the original BF Goodrich All-Terrain 285/70R17 tires (17″ Tundra Wheels & BFG A/T Tires). However those were not the first, nor the best, set of TRD Rock Warrior wheels I have purchased. The Cooper S/T MAXX trial started last summer and has drug on for a while.
Cooper Discoverer S/T MAXX LT275/70R18E with Tundra SR5 18" wheel
The reasons for buying the 18-inch Tundra SR5 wheels was because I wasn’t enthralled with the fake beadlock rings on the Rock Warrior wheels (Goodbye Bling Rings), and because finding a set of 17-inch TRD second generation Tundra wheels for a reasonable price seemed nearly impossible. Most of the sets on Craig’s List were almost new, with almost new tires, and guys wanted almost new prices, upwards of $1,500 for the tires and wheels. No thanks. In addition to being far more than I was willing to spend, because I’m not a BFG A/T fan (not a hater, just not a fan) I really didn’t want to pay anything for BFG A/T take-off tires.
There were two issues with the 18-inch Cooper S/T MAXXs: the drifting to the right, and the stiff ride from the rugged, short sidewalls. I could seek alignment solutions for the pulling—which I doubted would work—but how could I soften the ride of the stiff, short sidewall tires without letting too much air out? The stout construction of the S/T MAXX appeals to me, there is a time and application for these tires and I wanted a set, but the 18-inch 275s were rougher that I cared to drive on.
After deciding I wasn’t going to keep the 275/70R18s, and to take advantage of Discount Tire’s excellent exchange policy, the question was exchange them for what? Another set of F-C II? That seemed a bit silly, since my existing set was almost new, and I’d rather have one set of mild treads and another more aggressive. Though I knew a second set of F-C II wasn’t going to pull to the right and wouldn’t be a waste of money. Since I’d been down this road several times with the 4Runner, I was confident I knew the unhappy ending.
Summer I80 Road Construction
The First Set of TRD 17-Inch Rock Warrior Wheels
Knowing my dissatisfaction with the 18-inch sidewalls, early one morning my friend Frank inquired about finding a second set of 17-inch TRD wheels. I quickly dismissed his idea, telling him via email I had looked and they were all too expensive… But I decided to look again, and hidden among all the ridiculously expensive was one reasonably priced set at an independent tire dealer in Sacramento, just a couple hours away (thank you Frank). I was the first person to contact the seller, told him I’d be there in a couple hours if he would hold them for me.
A rural road side trip in search of Dutch Bros. Coffee
Though there was summer road construction in the Sierras, and the several thousand vertical feet lost and gained during the 228 miles of travel, careful use of my right foot allowed the Tundra to squeeze 17.88 miles from each gallon.
TRD beadlock ring scuffing
The wheels were not perfect, but in hindsight they are the best set I’ve purchased thus far. There were a few scuffs on the fake beak lock rings from careless handling (which helped me to negotiate a lower price), and three of four spring clips that secure the center caps were missing, which I didn’t notice until I was home. But overall they were a very nice set the will likely stay with the Tundra as long as it lives in my barn.
TRD Rock Warrior 17-in. beadlock ring gouges.TRD Tundra Rock Warrior 17-in. take-offs
With another set of 17s in the shop I didn’t know what I was going to exchange the S/T MAXX for, but I knew they were not going to be 18-inch tires.
Conventional wisdom regarding radial tire pull says that if a tire is the source of the pulling problem it can be diagnosed by using a specific procedure.
-Rotate the front tires side-to-side. If the vehicle goes in the opposite direction, it’s one of the front tires. If the vehicle goes in the same direction the pulling is from one of the rear tires, or is not a tire-related problem. There are more steps, but you can read them on The TireRack’s Pulling Tire Diagnosis PDF.
Though I have been through this procedure a few times before, I printed the PDF to insure I was following the steps exactly and made notes during the process. Guess what? The Tundra still pulled to the right, so I jumbled the position of the tires again and adjusted the tire pressure. Regardless of the position of the tires or PSI, the truck still drifted to the right rather quickly. So is there a chassis or alignment problem if there isn’t a tire problem?
Based on my experiences with my 4Runner I was quite confident that my alignment settings were fine, and not the source of the pulling problem, at least not directly. After numerous alignment adjustments attempting to redirect tire pull on the 4Runner (mostly cross-caster adjustments) some tires would still pull right while others would not. In fact depending on the tire and/or tread pattern, some tires required relatively high cross-caster while others needed very little. Using OE wheels, and in the case of the Tundra, OE sized tires, removes another variable that can make tire pull diagnosis difficult on modified vehicles. Are my modified chassis bent or broken, or are there simply compatibility issues with some tires and platforms?
Toyo M55 and Toyo M/T. Two tires that have caused tire pull on my 4Runner, but not on other trucks.
The Toyo M/T is known to cause a pull or drift on Dodge trucks, are these trucks broken too? My point is that even though the standard and accepted tire-pull diagnosis procedure might indicate the problem is not with the tires, that doesn’t mean there is a problem with the chassis. Having a second set of mounted and balanced tires has helped me confirm this a couple times. The tires may not be defective, but they may still cause a pulling problem on your truck and that doesn’t necessarily mean your truck is damaged or out of adjustment.
My favorite all-around tire remains the Dick Cepek F-C II. The Tundra’s alignment settings were working reasonably well with the F-C II and I was not willing to make changes that might improve the pulling with the S/T MAXXs at the cost of hurting drivability with the F-C IIs. Having two sets of tires isn’t practical if you need different alignment settings for each set.
All thirty-threes are not created equal, because they’re not all exactly thirty-three inches tall. The very common 285s are typically 32.8-inches tall while 255/85R16s are almost always 33.3+ inches; the Toyo M/T is 33.5-inches! Removing the Dick Cepek F-C II 17-inch 285s, slapping-on the 18-inch Cooper S/T MAXXs, and taking a few measurements showed that the taller 275/70R18 MAXXs were good for 3/16″ of additional clearance under the rear differential. Nice.
My initial S/T MAXX drive was on a test loop I typically travel after any tire, wheel, air pressure, alignment, or other drivability changes are implemented. It’s several miles long and includes city streets, rural highway, interstate freeway, and sometimes just a minuscule amount of dirt for photos. The route and terrain are familiar, as is the vehicle platform, what’s being evaluated is the change, in this case, tires.
LT275/70R18E Cooper S/T MAXX, slightly taller than most 285s.
Noise
What noise? Articulating tire noise can be a challenge, as vehicles have different levels of insulation and sound deadening, and drivers have their biases and tolerance or lack thereof for noise. With several back-to-back tire tests under my belt the S/T MAXX is clearly one of the quietest traction tires I’ve ever had the pleasure to drive on. The volume and tone is similar to my beloved Dick Cepek F-C II, but a bit quieter, and the MAXX is certainly quieter than the standard Cooper S/T. Comparing the S/T MAXX to the super popular BF Goodrich A/T is tough. While I currently have a set of used BFG A/Ts, I have few personal miles on them and I’m not a BFG A/T fan. I’ll go out on a strong limb and say the new S/T MAXXs are louder than the BFG A/T, but not much. For a tire that offers as much traction and void (much more than the BF Goodrich A/T) the Cooper S/T MAXX is an amazingly quiet tire and well worth the little noise it makes.
LT275/70R18 S/T MAXX on Tundra SR5 wheel
Stiff
As noted in my introduction, the ArmorTek3® carcass construction and 3-ply sidewalls of the S/T MAXX are stiff. This can be great if this is a feature you are looking for, or a negative if you prefer a more compliant ride and/or a lighter tire. (If you are new to this blog or subject, read Wheels, Tires, and Sidewalls from Jan. 30, 2012.) In addition to the intentionally rugged design of the S/T MAXX, using 18-inch wheels with only a 33-inch tire adds to the lack of sidewall flex.
One of my strong dislikes for tall wheels on light-trucks is manifested by this situation: a relatively tall tire (33+), with a relatively short sidewall doesn’t offer the same off-highway flex and performance available from a taller sidewall. The same height tire on a 16-inch rim would yield an additional inch of sidewall to drive and flex on; this is not a small difference. If you already use and like the firmness of a load-range E sidewalls then the stiffness of the S/T MAXX (similar to the Toyo M/T) may not bother you, particularly if you don’t have to run it on a tall wheel. However, if you prefer a more compliant ride or a lighter tire you might reconsider the MAXX. What do you want, and what do you need for your application?
S/T MAXX with Old Man Emu (OME) suspension.
Pulling To The Right
Several years ago I rarely experienced tire pull problems with my trucks, however they are all live-axle 4WDs. Starting with my 2006 V8 4Runner and now continuing with this Tundra, I’ve experienced a pull (or drift) to the right with certain tires but not with others. Both of these IFS four-wheel-drives have alignment settings and geometry that are equal to or better than when new.
Aftermarket upper-control-arms are employed and expertly adjusted, though invariably some tires cause a very noticeable drift or pull to the right. I’ve spent countless hours and dollars to try and understand, identify, and combat this situation on these Toyota 4WDs. In short, my work involved many trial-and-error alignment adjustments, tire & wheels swaps, rotations, and tire pressure changes, all of which did not correct the problem. Some tires would still pull right, some terribly so.
How bad is the pull or drift? On a straight section of freeway with little road crown, at 65 miles-per-hour, releasing the steering wheel will result in crossing the right lane-line in about 3-seconds. Three seconds! I’m a strong advocate of keeping one, if not two hands on the wheel, and paying attention to the task at hand when driving. But I also like my vehicles to have very neutral handling, heading straight down the road unless instructed otherwise. Modified or not, I require my vehicles to drive almost perfectly on-highway. For comparison, depending on the road, wind, and other variables, with the same alignment settings Dick Cepek F-C II tires would continue straight for 8–10 seconds with no-hands.
Some readers may observe that the wheels are not identical. OE 17-inch forged TRD wheels are being used for the F-C II, while the MAXXs are mounted on 18-inch SR5 wheels, and there is probably a slight difference in backspacing. Is that part of the problem? I doubt it, though I did consider of this difference, and have a plan.
After an interlude, there will be more Cooper S/T MAXX commentary in the future—first we have to drive there.
