Rear tires for Murci

if you buy michelin, look at the actual spec sheet of the tire and you will see that there is considerable difference in diameter vs. the pirellis (although they are both 335/30/18) which may affect the ratio between front and rear -unless you're RWD and don't care about it. i recall i had to consider this and the reason i didn't buy the PS2 when replacing my murcie tires -at that time it was still AWD.

 

 

Thanks, which tires did you end up going with?

Looking for tires now...is the PS2 no longer available in stock sizes? Are the SuperSports ever going to be made?

PS2 is available in 335/30R18, but the overall diameter difference between front and rear tires is outside the percentage of what the AWD allows.

 

BFGoodrich KDW is the cheapest option for tires.

PS2 is available in 335/30R18, but the overall diameter difference between front and rear tires is outside the percentage of what the AWD allows.

 

BFGoodrich KDW is the cheapest option for tires.

 

Thanks Nick

 

How is that BFG KDW tire? Anyone running those? The OEM Rossos diameters are 24.5 and 26.1 giving a ratio of 0.94. The KDW diameters are 24.7 and 25.0, giving a ration of 0.95. Are these numbers and calculations correct?

I had these tires on my Grand National and was not a fan of them. Buuuut they are so cheap in comparison to other tires available for the Murci, that they are a good financial option.

 

Since my car's rwd, I'm leaning heavily towards the PS2. My Viper had PS2s and I was very happy with its performance and life.

So it's ok to just buy the fronts or just the rears...we don't have to buy the whole set of 4 tires correct? If the rears are at 40% and just buy new fronts, that will not impact the AWD right? Thanks

I sure am!

What hre wheels are you selling, pics, price?

You should be okay going with a new set of rears. However, back in my Subaru days, it was a big no-no to get some new tires. But since the Murci seems to eat through rears and never wear the fronts, you should be okay.

if you buy michelin, look at the actual spec sheet of the tire and you will see that there is considerable difference in diameter vs. the pirellis (although they are both 335/30/18) which may affect the ratio between front and rear -unless you're RWD and don't care about it. i recall i had to consider this and the reason i didn't buy the PS2 when replacing my murcie tires -at that time it was still AWD.

 

Really? What kind of difference are we talking about? Moreover, what's the point of labelling them w/ certain specificiation then? i.e. the diameters are not strictly (33.5cm x 30% x 2) + (18 x 2.54) = 65.82cm?

 

Now that I've been thru the drama of locating the right front tires, I'm trying to plan ahead for the replacement of my rear tires: 355/25/19 which looks very challenging as well.

All different tire manufacturers measure their tires differently.

Just convert to RWD and you won't have to worry about diameters.

 

 

All different tire manufacturers measure their tires differently.

 

But the difference should be tiny right? Otherwise it sort of defeat the purpose of all the specifications?

Just convert to RWD and you won't have to worry about diameters.

 

I'm indeed on RWD already but at one point I do want to covert back to stock configuration: i.e. AWD and NOT having to switch off the traction control all the time. Hence I really want to get the tires right

But the difference should be tiny right? Otherwise it sort of defeat the purpose of all the specifications?

I never understood why they were all different. But they are.

 

Yes, it seems that the current way defeats the purpose of exact specifications.

I never understood why they were all different. But they are.

 

Yes, it seems that the current way defeats the purpose of exact specifications.

 

This just adds additional complications in terms of locating new tires. Any idea what kind of 'difference' are we talking about? I'm already having hard time finding replacement tires, not even sure whether I can afford to be choosy. Yokohama was the ONLY 245/30/19 I can get my hands on and now with this thread I'm worried when it comes time to find replacement for my P-zero 355/25/19...

Just compare whichever tires you want to run, find their actual height on Tire Rack, then see if their difference falls within the threshold.

Threshold: 1.161417" to 1.437008" difference in size

345/30R19 has a lot of options

 

Michelin SS

345/30/R19 - 27.2"

235/30/R19 - 24.6"

Difference = 2.6 - too tall

 

345/30/R19 - 27.2"

235/35/R19 - 25.5"

Difference = 1.7" - too tall

 

345/30/R19 - 27.2"

235/40/R19 - 26.4"

Difference = .08" - too short

 

345/30/R19 - 27.2"

245/35/R19 - 25.8"

Difference = 1.4" - WINNER!

Just compare whichever tires you want to run, find their actual height on Tire Rack, then see if their difference falls within the threshold.

Threshold: 1.161417" to 1.437008" difference in size

345/30R19 has a lot of options

 

Michelin SS

345/30/R19 - 27.2"

235/30/R19 - 24.6"

Difference = 2.6 - too tall

 

345/30/R19 - 27.2"

235/35/R19 - 25.5"

Difference = 1.7" - too tall

 

345/30/R19 - 27.2"

235/40/R19 - 26.4"

Difference = .08" - too short

 

345/30/R19 - 27.2"

245/35/R19 - 25.8"

Difference = 1.4" - WINNER!

 

Good point. I was trying to keep the actual diameters to be as close to the stock config as possible by going w/ the 245/30/19 + 355/25/19 combo. But I guess if the tires are impossible to find, then I'll go w/ 245/35/19 + 345/30/19. I would imagine the spec. above is for Michelin Pilot Super Sport?

Good point. I was trying to keep the actual diameters to be as close to the stock config as possible by going w/ the 245/30/19 + 355/25/19 combo. But I guess if the tires are impossible to find, then I'll go w/ 245/35/19 + 345/30/19. I would imagine the spec. above is for Michelin Pilot Super Sport?

 

Actually I looked up all the tires combo for 245/35/19 + 345/30/19! It does look like there're upto 0.3" difference among different manufacturers which could be quite significant, especially for the purpose of this calculation.

 

For 345/30/19 we don't really have that many choices, just Michelin Pilot SPot PS2 and Pilot Super Sport, both at 27.2". 245/35/19 on the other hand got quite a few choices, ranging from 25.7" to 26". So naturally one would want the largest 245 to minimize the 'difference'.

 

One thing that I do notice is that these figures are all rounded to the nearest 0.1" so theoretically one will 'think' that any of the 25.8 (the majority of them!) would make 27.2 - 25.8 = 1.4" hence within 1.1615" & 1.4370" tolerance.

 

However, if you take the possibility of rounding, assuming the 27.2 CAN indeed be 27.24 and 25.8 can indeed be 25.75, then we'll have a difference of 1.49" which is over the limit.

 

So to play safe, one would need 25.9" front to go with 27.2" rear which leaves us the choice of Pirelli P zero or Dunlop SP Sport Maxx TT!!!

 

Or we'll need to track down the spec to the nearest 0.01".... Oh boy this is a LOT more challenging that I imagined!

 

Good point. I was trying to keep the actual diameters to be as close to the stock config as possible by going w/ the 245/30/19 + 355/25/19 combo. But I guess if the tires are impossible to find, then I'll go w/ 245/35/19 + 345/30/19. I would imagine the spec. above is for Michelin Pilot Super Sport?

Yeah, it's a total PITA.

 

I used the SS as an example. . . and the fact I wish they fit 18" wheels.

Yes,, is you aren't close enough, good bye front diff.

For future reference, I made a new page for the LamboTech blog. It should make finding the correct tire size a little easier.

http://lambodiy.blogspot.com/p/correct-tire-size.html

Actually was just thinking about this a little more: What would a the thread wear affect the actual size of the tire? i.e. imagine a brand new Michelin SS 345/30/R19 at 27.2". What would the size be if it's close to the end of its life? If there's a significant difference, then one would imagine we need to factor in potential difference between new front tire and very used up rear or vice versa and take that into account for setting up the 'boundaries'?

 

I can't imagine if the owner made a mistake of not getting all four new tires at the same time then frying the differential...

 

 

Actually was just thinking about this a little more: What would a the thread wear affect the actual size of the tire? i.e. imagine a brand new Michelin SS 345/30/R19 at 27.2". What would the size be if it's close to the end of its life? If there's a significant difference, then one would imagine we need to factor in potential difference between new front tire and very used up rear or vice versa and take that into account for setting up the 'boundaries'?

 

I can't imagine if the owner made a mistake of not getting all four new tires at the same time then frying the differential...

A new tire Vs a worn tire is a big issue. That is why on all all wheel drive vehicles where you can't rotate the tires to keep wear even it is recommended to replace all 4 at the same time.

^ that

Thinking about goign to the PS2's myself, I are was a fan of them on my viper. Anyone want to give me a decent price for my OEM Tires? They have about 2800 miles on them. The tread blocks seem like they are going to last forever (a bad thing, cuz I want to replace them), I keep thinking I'll drive my car enough to wear them off, but hasnt happened yet