Tire Size Issues

tires

#1

Tires for 1998 Jeep Grand Cherokee Laredo.
Takes 225/75 R 15. Size is not available in LTX MS2 Michelin, the top rated tire. It has MS on it now, becoming worn out.
This is used primarily as a car (no heavy hauling or off road use).
So, what to do? There are a few brands that come in this size, not many. They apparently fall short of the Michelins in
a number of ways. There is available a 235 in the MS2, but I am concerned about going oversize even a little bit,
as various problems may happen. Any knowledgeable comments?


#2

What about the Firestone Destination LE-2? It’s highly ranked in Tirerack.com owner surveys.

One of the owners wrote a positive review that said the tires “Rank as good as top rated Michelin LTX M/S which I have always purchased in past when needing new tires.”

And Tirerack.com has several other tires in the same size.


#3

Yeah, that one is my alternative. One thing is, TireRack reviews and surveys always look better when the tires are new models, and tend to sink downward as more reviews come in. Look at the Hankook H727 and the Michelin Defender–not as golden as they looked at the start.
Consumer Reports only shows the LE, not the LE2–but the LE doesn’t look so good. Mid-Pack.


#4
There is available a 235 in the MS2, but I am concerned about going oversize even a little bit, as various problems may happen. Any knowledgeable comments?

Why? 235’s are just a little wider. I wouldn’t worry about it.

I personally wouldn’t get hung up on buying Michelin truck tires. They are very good tires…and I use to buy them…but you can get the same (or close to the same) performance for about 40% cheaper. I’ve been running Cooper tires for over 20 years now. I’d compare their truck tires to Michelin any day.


#5

Yeah, 235’s should be fine, they are only 10mm (3/8’s inch) wider. Put me in the Firestone Destination LE2 camp. I have a set with 3000 miles now on my truck. This set was preceded by 2 sets of the earlier Destination LE’s with 45 to 65,000 miles on each set. It is a good tire. Quiet, long wearing, good on road traction wet and dry, decent off road traction if you don’t ask too much and good price.


#6

Anyone know about snow and LE2?


#7

From a tire rack review:

“I installed a set of the Destination LE2’s on my '08 Highlander last August. Overall performance has been exceptional and their traction was so good in the early snows we received in my region that I never bother to rotate them off in favor of the Blizzak set I have for the winter. I would buy these again in a heart beat.”


#8

I wouldn’t use the 235s without understanding your wheels better. First, the OE widths are 215-mm and 225-mm. Are they on the same wheel or did Jeep provide a 7-inch wide rim for the 215s and an 8-inch rim for the 225s? If they are on the same rim and it is a 7-inch rim, I’m not sure the 235 will fit. Also, if the width is increased 10-mm, the height should be reduced by 5% to 10% to keep the diameter about the same. Even though the tires are just a bit wider, they are als much taller. Maybe you should forget about the LTX MS2 tires. Here is a tire size calculator to show you how the size changes:

You might to to Barry’s Tire Tech and ask Barry what he thinks.


#9

Barry thinks that going to a 235 seems a reasonable thing to do.


#10
I'm not sure the 235 will fit. Also

I’ve had many sets of 235’s over the years running on 7" rims. They should easily fit on most 7" to 9" rims.

Also, if the width is increased 10-mm, the height should be reduced by 5% to 10% to keep the diameter about the same.

The OP never mentioned the aspect ratio. If the aspect ratio stays the same (75)…then the height will INCREASE with the wider tires. NOT decrease. Going from a 225/75-15 to 235/75-15 the height will INCREASE by about 1/2".

Now if you go to a 235/70-15…the height will decrease by a third of an inche.


#11

why would the height increase? if the 75 stayed the same , is that not the height number?

I admit I don t quite understand the tire numbering system very well.

enlighten me…

I ve always run 235 75 15 on my pickup, but have bought 225s on occasion,


#12

@wesw The 75 means 75% of the sidewall width is the height from the rim to the tread. so 225 x 0.75 = 168.8mm, convert to inches by dividing by 25.4 = 6.64 in, so the diameter is 2 x 6.64 +15 (for the wheel dia) = 28.3 inches For a 235/70/15 the dia is 27.95 inches The dimensions are never perfect and vary a little from tire to tire but is is close enough. Welcome to Minglish, the world of mixed metric and English measurements!


#13
why would the height increase? if the 75 stayed the same , is that not the height number?

It’s the aspect ratio of width to height.


#14

gotcha, thanks


#15

Tires have the most disjointed, unintelligible, and confusing system of identification imaginable. The width (from inflated sidewall to sidewall) is in mm, the sidewall height is in a ratio, and the rim size is in inches. All the other data on tires is “coded” more deeply than a top secret Washington foreign affairs message. The evolution of all this has long been a mystery to me.

There are numerous websites to help explain the meanings of tire indicators. That alone is testimony to the truth of my contention.


#16

And then there’s truck tires…

31x10-15

31" high x 10" wide - mounted on a 15" rim. Much simpler if you ask me.


#17

Truck tire measurements make perfect sense for us. Passenger car tires used to be in inches ie 8.50 X 15. What is the conversion formula for the interim letter X number X inches ie G70 X 15? I’m sure some day the US and UK will join the rest of the world but then we would lose one of our confusing discussions.


#18

“X” is the symbol for “by”. 8.50 X 15 means 8.50" by 15".
You were joking, right?


#19

It became ridiculous 10 years ago when tire retailers ran out of shelf-space…It hasn’t improved any…There is always a little wiggle room with tire sizing…


#20

I had michelin, and downgraded to BF Goodrich Long Trail TA, seems a fine tire, and available in your size. Ride is a tad harder, seem to have lost 1 or 2 mpg, but was recommended to save money over Michelin by my mechanic.