235/85-16 or 245/75-16 Duratracs?

[pcjeeper]

I've got a 2004 Ford Explorer Sport-Trac that is in need of some new shoes. It has the stock 4.0 V6, 4.11 gearing, and I'll be running stock alloy wheels.

I am pretty well sold on the Duratracs -- we live in Montana and these will be three season tires (we swap to Blizzaks for the winter months) -- but I am open to suggestions as long as they can manage the occasional snowy day. The 245's are just a touch over stock height (255/70-16) and a touch narrower...the 235's are quite a bit taller and a bit narrower than stock. But, either tire should fit with the stock suspension (though the 235's might be a little tight). Initial price point is pretty much identical. My questions are these:

1) Am I going to hate the E load rating on the Sport-Trac if I go with the 235?
2) The 235's are 7 lbs. heavier per tire -- while I know this will adversely affect MPG, is it going to kill my range and impact the truck's handling significantly?
3) Any other concerns I should be aware of?

Thanks for the advice, particularly if you've run either of these tires.

 

[gypsybarber]

I worked at Les Schwab for about a year and a half, for those not on the west coast they are a tire company, the largest family owned tire company in the nation. I have a little experience and would happily answer any tire/suspension questions.

1 Hate may be a strong word. Even when running 35 psi in the 10 ply they are going to be hard and "jouncy". When you have a heavier truck that can flex the tire, they feel about the same as a lower ply tire on a lighter vehicle. When I run a e load rating tire on my dually it feels about the same as a 6 ply on my half ton short bed. Good news is better protection for rock/impact damage. I had some 10 plys on my half ton short bed and they are a little rough. I was willing to live with it.

2 They will be heavier, but because they are bigger around, you may actually see a bit of increase in mpg and range. My dually is stock with a 225 75 16 i think, but I run 235 85 16 and my speedo reads 5mph slower than my actual ground speed (verified with 2 separate gps units and a newer vehicle pace car) so when driving the same actual ground speed I turn less rpms, since the bigger tire turns fewer times in the same distance. Plus you can play with pressure to find the sweet spot in the tire (least rolling resistance, I'll do a whole other post on how to ascertain rolling resistance) which will net you the best mileage. I run 62-64psi in my dually unless I'm towing since it nets the best mileage (15.8 hwy last I checked btw not bad for a 85 crew cab 4wd dually long utility bed gmc with a 6.2 Detroit Diesel)

3 Rule of thumb - a narrower taller tire imparts more force on the ground than a shorter wider tire. There are 2 trains of thought where tire size is concerned: some people like to skim on the top of the dirt and "float" over obstacles, some like to dig and climb. I personally prefer pizza cutters. I drive a heavy truck (fully loaded for a trip with the family and full of fuel I'm around 10,000) so I run tall skinnies... Dig and climb baby. I'd like to turn you onto a tire. The tire I run is the Toyo M55. http://toyotires.com/tire/pattern/m-55-on-off-road-commercial-traction-tires I put on hundreds of these when I worked for Les Schwab in Nevada on trucks at the gold mines and these things are tough. Great mud tires, not terribly loud as far as mud tires go, about like an aggressive all terrain, snow rated so a little bit at the beginning of the snow season they will do fine (i drove rigs when I worked at the mine that had these all over the place even up to 3 feet of snow just fine) and they wear well on the street. regular rotation and correct alignment I wouldn't be surprised to see 40 000 miles or more on them, not bad for a mud tire.

 

[chilliwak]

Hello Gypsybarber and welcome to the forum. I am sorry for high-jacking this thread but I have a tire question. I am running 11 by 35 inch Bf Ta,s on a 15 inch rim and need some `E´rated tires for the rear. What would be the size tire that would have the same diameter as the 35s? I hear that I need to go to a 18 inch rim to get the right size `E´rated tire. I am looking at getting the DuraTracs. New rims are not a problem for me. Once again sorry for jacking the thread....

 

[Erik N]

Chili, see this table:
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=53

 

[BCHauler]

pcjeeper - a lot will depend on the kind of ride you prefer. If you like comfort and a more car-like ride, then you probably want to avoid the e-rated tires. I put LT235/85/16s on my 99 f150 after I bought it, replacing the p235/70/16 that were on it. I greatly prefer the e-rated tire but I like to use my truck as a truck, and tend to prefer a firmer, truck-like ride. Your sporttrac is probably close to my f150 weight wise. I found a greater difference in shock choice than tires when it comes to ride, as you can vary inflation to adjust the ride somewhat.

 

[chilliwak]

Thank you for posting that tire link Erik!

 

[mortonm]

For what its worth I run 235 85R16 on my 2001 Xterra. Probably weighs about the same as your explorer

I haven't had any issues with them feeling too harsh or stiff. I also came from a lowered VW GTI with 40 series tires.

I love the 235 85. Wouldn't run any other size. If they fit well then I would say go for it.