Well I did it. Decided that my long-running Nokian W/R's needed replaced and after much searching decided I was going to give the Definity Dakota M/T (Pep Boys house branded name on a Cooper built tire) a try.

I decided that since I was returning to stock size of 265/75-16 with the M/T vs. my old Nokian's which were 265/70-16 I wasn't going to try and push the 33" area yet.

So on Friday night in Houston I paid my roughly $600 for the fully warrantied, lifetime balanced and so on, Dakota M/T's and had them installed. I'll be getting roughly $120 of that back - so on the whole it seems a decent deal.

I was leaving the store an hour later. On the way home I thought "this was the biggest @#$@# mistake I've made in a long time!" and was horrified by how not round they were. Truck was in my opinion not safe. But as Pepboys was closed already for the evening I had little choice, so when I got home I experimented. Bringing the tire pressure up from 32 to 42 seems to get rid of a lot of the wheel/hop and oscilations - but not all of them. 48, 55, 62mphs were all still bad with shaky steering wheel and the truck pitching sideways on hard breaking tests .

Got up next morning and back to PepBoys to sort it out. After they made me wait 2.5hrs for attention - we got down to the bottom of the issue. Once again the non-hubcentric 4Runner wheel was/is root cause. I basically had to stand there in the service bay working the tire balancer with the manager - because his staff would say "see the wheel is bent" because it was of course traveling in an oval shape. Mind you we did this for each of the 4 whls. I would then draw their attention to the line of the hub contrasted to the hub of the balancer and point out that it wasn't round there either proving that it wasn't mated correctly.

Total time: 4hrs later we re-re-rebalanced all 4 tires and things are almost right. I think if I find a shop with a lug-centric adapter and have it done correctly they will be perfectly smooth, as it is right now it's barely detectable to driver, not at all to passenger.

Road noise: holy cr@p these are quiet M/T's. Granted I'm willing to bet they will become louder - but they are barely louder than the street tread I had on before at highway speeds, windows up or down. Yes you hear them on surface roads - but that's to be expected and it's somewhat pleasant.

Inflation: seems to be critical and I'm still finding the sweet spot. Right now running 38psi front 35psi rear and getting good contact patch across surface of tire, and has increased straight line stability under hard breaking.

Only time will tell how they feel in long run - about 150miles on them so far but I've changed my mind from thinking it was a huge mistake, to thinking it's a good deal. Perhaps someday I'll even let the truck see mud to investigate what the tire was designed for. I bought them cause they look cool, and not afraid to admit it.

 

Not bad looking. Hope you get the kinks worked out.

Pep Boys sucks, I have had repeated experiences where the service was bad. I thought it was just mine here in my town but I guess not. Its funny how there are so many bad mechanics out there. Which is one of the reasons I have found this site to be a blessing, its enabled me to do my own work.

Good luck with the tire battle and let us know how it goes as more miles get put on it.

 

yea they do look good, and sorry to hear about pep boys giving you trouble with your wheels. does it ride like street tires?

 

Ride like street tires? Er well not exactly. You can definitely tell that you've large flexible tread blocks in between you and the road. The compliance over sharp high-speed (highway expansion joints) is much better due to having those tread blocks for compression.

So it's a bit of give and take. I like the traightline ride better, but am giving up some roadholding in turns and giving up a little breaking performance. Perhaps that will get better as the rubber heat-cycles over the 1st 1,000 miles.

 

Glad you got things worked out. Those look like they have some nice tread. Pep Boys around here closed.

Rob

 

Here's an update. I've got about 1500miles on them now. I finally gave up on PepBoys and paid the local Toyota dealer to balance the tires. Best $30 I've spent. Now they ride smooooooth, with no bounce.

Noise has remained quite quiet - no passengers have noticed tire noise in the cabin with the windows up. You do hear it with windows down - but nothing like you'd expect looking at the tread.

Here's the totally unexpected thing: my MPG has dropped by 2 at highway speeds. I though my tank wasn't living up to it's range expectations - but after driving 300miles of highway this weekend all on same day - I KNOW it's dropped. 75mph cruise results in an actual fuel burn of 17.3mpg. So what's changed?

My old tires were Nokian WR's (street tread) and were sized 265/70-16, and these are now Mud tread sized 265/75-16. So I knew the speedo was off by 2mph indicated on the old tires which at 77mph constant cruise would give me 20.5-21mpg depending on weather.

All else being equal - unless my 02's have gone dead (truck just passed inspection and no emissions issues found) then all I can figure is that the larger tread blocks create so much rolling resistance that it's cause the mpg to drop a lot.

For refference I'm running those tires at 36psi front, 32 rear. I've got a nice even contact patch across full width of treadblocks in front and rear so inflation seems about right. But I've never had M/T's before.

Thoughts anyone? The emotional response in me would be as gas hits $4.50/gal I might think of having a second set of wheels & tires that are ugly highway tread (super low rolling resistance) just to recover the mileage.

 

Thanks for the update!

The mileage change could be a result of going from the 70 series tire size to the 75's. The 265/75-16s' are/should be about an inch taller than the 265/70-16's.

Here's a link to the comparison tool on Discount Tire's website, granted it's a ballpark estimate, as actual tires sizes may be different between manufacturers etc....

http://www.discounttire.com/dtcs/infoTireMath.dos

On a side-note, I've ran the Definty Dakota A/Ts for just over a year. I've already put about 35k on them and they are still showing strong treadlife. Although the service at PepBoys is usually OK at best, I've ran their tires on two different 4Runners with good results...

 

quattro - I went from a 265/65/17 to 265/70/17 (same as 265/70/16 to 265/75/16) and noticed a ~2MPG drop (calibrating for the bigger tire size). It is normal. The M/T's are heavier and larger, which takes more power to turn.

I would suggest getting a second set of wheels with all-season tires in the stock size of 265/70/16 or 245/75/16 (you can find another set for fairly cheap. They are all over craigslist).

 

dude a lot has changed

those fat lugs are eating yer gas mileage. plain and simple.

 

Yeah, Mud Terrains tend to use more fuel