Just installed a set of 15MM spacers on the rear of my MCS Gen3. Ready for a set of tires that will improve the ride comfort. Plan is to go with 225/45/17 (replacing the stock 205/45/17 RunFlats). Can anyone suggest a brand that will give a softer ride? Oh, will going with a 225/50/17 fit? I know it is 1.6" more diameter than the 45s. But I'm thinking the wider sidewall will offer more cushion. Thanks.

 

I doubt it will rub unless you lower it. Any non-runflat tire is going to feel better than the current tires. If you're looking for a great all around summer tire I recommend the Michelin Pilot Super Sport. If you want loads of grip and less tread life at a good price the Hankook RS-3 is a great choice.

 

Wider tire shouldn't matter. Like randonquickness said any non RF will ride better than any RF. They last way longer too, and cost half as much. The other big thing is wheel size. 16" softer than 17".

 

Overall diameter of replacement tires should be within ±3% of the factory specification. 225/45-17 is +2.9% larger in diameter than 205/45-17, but 4.2% larger than 175/65-15 (the factory 15" wheel tire size). 225/50-17 is 6.6% (way too much) larger in diameter than 205/45-17.

215/45-17 is the most common plus size replacement for 205/45-17.

The larger the tire diameter the slower acceleration.

 

I don't know about the other tires, but when I looked at 16" Pirelli's P7 that mine came with, their RFT have the same tread rating as their non-RFT. Since they are rated by the same manufacturer, doesn't that mean that they should last the same too? I think it was 500 A A or something like that.

edit: I looked it up, but couldn't find the non-runflat version with same size.
195/55R16 Cinturato P7 All Season 500 A A (RunFlat)
v.s.
195/55R16 Cinturato P7 All Season Plus 700 A A ( <-- maybe this is what I should be comparing mine to? )
195/45R16 Cinturato P7 All Season 500 A A (will have smaller diameter)
205/55R16 Cinturato P7 All Season 500 A A (will have larger diameter)

 

It does not appear that Pirelli thinks so:

245/40-18
P Zero Nero all season UQTG: 400, treadwear warranty: 45k miles
P Zero Nero all season runflat UQTG: 400, treadwear warranty: 30k miles

 

Is that because the warranty?

 

The lower warranty on the runflats strongly suggest they aren't going to last anywhere near as long as the non runflats. Pirelli is by no means unique in this non-correlation between UQTG, warranty, and actual wear. The UQTG wear numbers are ball park numbers at best, and just plain silly at their worst.

 

+1 for the MPSSs. I went with 215/45/17. No issues and I love them. I carry a spare wheel and tire on trips over 150 miles. Will use AAA if ever an issue on short trips. So far (20,000 miles) never had a problem. I use 38Front and 33-34Rear pressures on 2010 MCS around town.

 

Runflats will not last as long as non runflats, I don't care what brand it is. Mine were good runflats and I replaced them at about 28k. My non RFs were still on the car when I traded it in at 71k last year, with probably a year left on them. One tip to runflats: lower the tire pressure. Mine call for 38psi and I usually carry 34psi. I think it helps. My RFs feel subjectively similar to the non RFs I had on the 2007 MCS. Both cars had suspension upgrades.

 

When you say "good" tires, are you talking about ride quality and grip or gas mileage or noise or wear? I think lot of people will be meaning "grip" here while eco/gas saver forums will talk about tread wear and gas mileage. I'm mostly interested in tread wear and noise since I never track or drive aggressive.

Also, wouldn't deflating the runflats cause them to wear out too soon? Maybe that's why you only got 28k on your first set?

 

I'm talking about how much they cost (about $250/tire on the 2007, and my 2014). They all get the same gas mileage. I doubt noise differs. Handling probabaly differs. My current tires are known to be grippy, summer tires. I could care less how long they last. I doubt that reducing the pressure by 10% does much in terms of tread wear.

 

215/45-17 is same diameter as 205/45-17. But a 225 tire is wider than a 205 tire.

 

Not true ... it's 1.2% larger in diameter.

Tire Size Comparison

 

^ a lot of people still don't understand tire sizing. They think a 45 sidewall is the same across the board when in fact the first two numbers i.e. 205/45 represent a ratio

 

That's correct. The 45 means it is 45% of the width. So 45% of 205mm is a smaller number than 45% of 215mm.

 

I just have to post this. On my '15 MCS with 17" runflats, the ride is better than my '12 MCS with 195/55x16 Michelen AS3's. Also, on my '12, I got rid of the runflats at 32,000 miles, but they had many miles left on them.
While the runflats were so obviously harsh and ill handling on rough roads on my '08 and '12 MINI's, on my '15, the handling is very good on rough roads and doesn't tramline like the R56's did with runflats.
Just a thought.

 

I like the ones I have (Dunlap Sport SP1) a WHOLE lot better than the ones on my 2007.

 

I'll sell you mine! only 6k miles on them

 

dpcompt,
Which runflats do you have now?

 

They're Hankooks, 205/45x17. I run them at standard psi, 38f 35r. I can't tell if its the tires or the '15S's suspension improvements, but the improvement ( with no loss in handling) is very pronounced. When test driving the new "s", I drove both my '12S with the 16" AS3"s and the new car on the same bumpy roads in Sacramento, to get a true comparison.