My daughter's 2012 MCS (which I get to babysit while she is away at school!) has 20k miles and the OEM run flats are quickly going downhill.

I've decided to replace them with Michelin Pilot Sport A/S. The OEM size is P195/55R-16 however it looks like I can also use the following sizes:

205/50R-16
205/55R-16

Does anyone know what the difference in ride quality will be with the various sizes???

Cheers!

 

I went with the 195's and they looks great and ride awesome. After seeing them installed, I'm happy I didn't go with 205's, the 195 look to fit the wheels just right.

 

The 205/55 will have the best ride but it will be by a small margin. Each size will be dramatically better than your run-flats.

 

Thanks for the feedback!

Sorry for just stating "ride quality" in my Q. I know that all of these tires will perform better than the Contis that can't come off soon enough. Why take a fine ride and put that crap on it?!?!?!

What I really meant is which size will allow the MCS to properly enjoy a spirited drive without flying off of the road?

I believe that the larger size may fill out the wheel in the MCS below...although it would be nice if someone could confirm that they have successfully installed the 205/55R-16 on the wheels of this MCS...

 

I've been running 205/55/16 for over 100k miles with no problems. There are many other people that run that size.

 

Of the three sizes 205/50-16 maximizes cornering ability due to wider tread (over 195) and lower center of gravity compared to 205/55. However, most people would not detect the difference while driving on public roads. In motorsports it would make a world of difference (where a one second advantage is huge).

 

Understood...I have more factors to consider than cornering...although we do have some twisties in this neck-of-the-woods...once again I've not specified much...I'll probably just go with the size that costs less....as you suggest, either one will be fine and the differences imperceptible to some/most of us.

Being really naive here: I wonder if anyone has tried to run 225/50R16 on their R56? Would that even fit?

Thanks again for your direction!

 

I'm running 225/50/16 and they fit fine on my stock ride height 2007 MCS -no rubbing at all.

 

Yes - I am running 225/50-16 summer performance tires (Honkook RS3's) and they fit perfectly on stock 16x6.5" ET48 rims. For the winter tires, I maintained the stock size with 195/55R-16 Blizzaks.

However, given the fact that you are focused on all-season tires and not performance summer rubber (a fairly sensible choice for your daughter's ride), I suspect outright performance in not your primary concern. Therefore, I would worry less about fitting another 10-30mm or rubber width onto those wheels, and err on side side of comfort and slightly better mileage that will be maintained with the stock 195mm wide tires. I pickup ~2 mpg when switching from summer to winter tires (disclaimer: many other variables in play than just the size).

The 55% profile sidewall will be a little more cushy than 50% profile sidewalls of alternative tire sizes.

Also compare the prices - stock 195/55R-16 may, or may not, be the cheapest.

Lastly, consider getting a quality tire-seal kit to go with non-RFT tires. I got one of each for all my RFT-delete cars: https://www.tirerack.com/accessories/detail.jsp?ID=38

a

P.S.: Now, if your daughter is into autoX-ing and DEs, than disregard the above recommendation entirely!

 

I went thru the same process on my 2011 R57 with 20k mileage a few months ago. I ended up going with the Michelin Pllot AS 3 205/50R. It's a great tire for that wheel and would highly recommend. Runs smoother, corners better and a much improved road feel. The tire is slightly smaller in diameter than the stock 195/55 r so the speedo is about 10% off but it's easy to calculate

 

We went from 205 45 17 Rtf to 225 45 17 non Rtf on two MCS's.
I know your talking 16" not 17", but a wider tire makes a big difference in traction and breaking distance in all weather conditions. I would not go with a lower profile (diameter) than stock unless you what to deal with bent rims or knocking the alignment out on potholes.

The pilot sports are great tires, but you may want to consider the Bridgestone S 04 an another great tire. In my experience firestone stores well match tire rack pricing after shipping cost and mounting. If you don't like the size or tire for any reason they will swoop them out for free.

P.S. A lot of mini guys also run the Bridgestone 760's.

 

Actually, speed would be only 1.77% higher than stock, which is reasonably close (anything within 2-3%).

Here are the diameters and speedometer deviations for the common 16" MINI tire size alternatives:
Tire size Diameter % Difference Actual speed @60 # of tires @TR
195/55-16 24.44" 0.00% 60.00 mph 51
205/55-16 24.88" 1.77% 61.06 mph 164
215/50-16 24.46" 0.08% 60.05 mph 3
225/50-16 24.86" 1.69% 61.01 mph 68

HTH,
a

 

That's a common misconception - wider tires make ZERO difference in traction or "putting more tire on the ground".

If you think it through, the total surface of the tire contact patches on all 4 corners are a function of car's weight, tire diameter, and tire pressure. ALL other things being equal, the area of the contact patch will remain the same.

Wider tires change the shape of the contact patch, making it wider and narrower (all other things being equal). In some ways it's better to have a wider and narrower contact patch (less contact patch distortion during cornering, runs at a lower slip angle, run cooler, etc), in others it's worse (wind and rolling resistance, earlier hydroplaning, greater weight, etc).

This is a gross over-simplification if a complicated problem that also has to account for side-wall stiffness and distortion under loads from multiple angles, tire compound and resistance to over-heating, tread patterns (and their distortion under load), differences in tire compound and pattern across the tire surface, tire carcass construction, optimal width of the wheel for a given tire width, slip angles, etc, etc.

Google for more info, or start here: http://www.roadandtrack.com/motorhea...t-tire-patches

Agree on recommendation for Brdigestones, though the one's I liked the most were RE11's. Wonderful performance and daily-driver summer tire. Better than R3's I tried next and still haven't worn off.

a

 

Great feedback and analysis...thanks again!

I'm sticking with Michelins as I've used Bridgestones (and Pirellis) on my 911SC and greatly prefer the Michelin tread for being quieter, longer lasting and delivering the street performance that I require.

The price analysis of the different sizes from TireRack is as follows:

195/55-16: $129.00 (per tire) = $516.00
205/50-16: $127.00 (per tire) = $508.00
205/55-16 H: $120.00 (per tire) = $480.00
205/55-16 V: $117.00 (per tire) = $468.00

I'm leaning towards the 205/55-16 H but still need to understand how MPG will differ between that size and the 195/55R-16 and the 205/50-16 sizes...

 

It's taller. That will help.
It's heavier. That will hurt.
The odometer will be understated by 2%. So will your calculated MPG.
The speedometer will also be understated by 2%. That will make it more accurate.

If you fit 205/55's the 24.9" diameter will shrink with wear and the difference in height between it and new 195/55's 24.4"diameter will disappear.

A new 205/50 is 24.1". Modify the above statements accordingly.

Analyze this enough and you will come to realize the single answer to all your questions is: "It all depends on how hard you flog the horses."

Is your daughter going to be ok with the loss of that (in)famous "go-kart" feel when the car doesn't turn as quickly in response to steering input?

 

I lost about 2 mpg when I switched from stock 195/55/16 to 205/55/16.

 

"Zero difference in traction" is a bit misleading.

From your link:
"Installing fatter tires widens the patch, but it also shortens it front-to-back. Because of this, cornering gains can be offset by diminished straight-line traction, including braking and hydroplaning resistance."

 

To answer your "flogging" Q: My daughter does not yet know how to flog and I have a couple of other cars that like to be driven like they were stolen so the MCS is not typically driven hard.

Also, while I have experienced the MCS' go-kart abilities, the run-flats dampen that experience so I've not properly been able to get the stupid smile on my face.

1 Q re 205/50-16: will they get better MPG than the 205/55-16 H???

 

While a decrease of 2MPG isn't terrible, it does give me pause.

How is the ride, handling noise of the 205/55/16 compared to the 195/55/16 (I'm assuming that those were run-flats)?

 

Yes, the 195/55/16 were the OEM tires. In my case, they were some Goodyear model.

Personally I was never bothered by the ride of the RFT, so I did not feel like the change to non-RFT produced some awe-inspiring change in the ride of the car. Judging from other's posts, I'm probably in a minority on that.

From a handling perspective, I felt like I could push a little harder through corners. However, I would attribute that more to the compounds used (2 summer tires and 2 AS so far) compared to the stock AS RFT. The extra width in theory helped some, but I suspect the rubber and tread design had more to do with it. That said, you do lose some of the "snap" of a rigid sidewall. The only time that was an issue for me was once on VIR when I could feel the tire roll over on a corner. Never felt it during street use.

As far as noise, all the tires I've had started out quiet. I'd say the Bridgestone RE970 AS I just put on are starting out the loudest of any I've tried so far, but they are still quiet and I'd say more quiet than the stock RFT. The Conti DWS didn't develop any noticeable road noise until sometime in the 40k+ miles range. The Conti DW never really developed any noticeable road noise. The Yoko S.Drives developed significant road noise starting at about 18k miles.

In terms of being able to push the hardest through corners, I'd rank the S.Drives as the best I've tried so far. However, I would rank the Conti DW as the best all around tire considering grip/handling, life, road noise. The Conti DWS were a compromise to get a longer life and performed as I expected - not quite as well as the DW. I've only had the new Bridgestones on for a couple thousand miles, so their results remain to be seen.

 

I'm thinking most of us would agree that modern high performance vehicles like Porsche, AMG and Super Car tire packages are highly researched and optimized by the manufactures to deliver the maximum performance for the vehicles intended use. I agree once the optimal tire size is reached on a vehicle for a given intent adding wider tires or putting more tire on the ground will not increase traction and is a common misconception, it will more than likely reduce the overall performance of the vehicle.


I'm sure you and Thereisnosubstitute would agree if he reduces his tire width by 50% on his 911SC traction under load will be reduced, hence add more width or putting more tires back on the ground will increase traction and overall performance. So the statement “wider tires make ZERO difference in traction” and “a wider tire makes a big difference in traction and breaking distance in all weather conditions” are both over simplifying as you stated.


In my experience with the “front wheel drive” R56 turbo, counter sizing the general purpose tires up a little did increase traction resulting in reduced wheel spin, less traction control activation and the associated torque steer under hard acceleration (on our far less than track quality public highways). I also experienced less ABS and stability control activation on wet pavement as a result of better traction, but I am not suggesting the stock tire size on Mini’s are deficient and not an overall well-balanced OEM fitment.

To be fair and balanced I also noted some other changes in the driving dynamics on the R56 turbo with the 225 45 17 that some Mini owners may not like. The wider tires increased the heaviness of the steering a little but most notably in sport mode, and the taller none RFT tires made a major improvement in ride quality but buffers some of that go-cart steering feel out.

With regards to the RE11’s, it’s my favorite Bridgestone performance tire also but felt the S-04 was a better balance of performance and mileage for my use.

 

Would you (lose some of that go-kart feel) get any rollover in hard cornering with say Michelin Pilot Super Sport 205/45/17?

 

The "gokart handling" feeling will be reduced when you lose the ultra-stiff sidewalls a runflat needs to support the weight of the car after complete loss of air.

You can keep a tire from rolling over onto the sidewall by adding more air. Dunlop Star Specs required 49lbs in the front to keep from rolling over on my R56 when autocrossing. The runflats on my Roadster S don't grip well enough to roll over. They slide on smooth surfaces and hop sideways on bumpy surfaces under moderate cornering.

 

This is my take, the max performance and Extreme Performance summer tire are designed with stiff side walls to deliver a high level of steering response, support high loads in cornering and deliver max traction. The RFT is designed with stiff side walls to support the vehicle without tire air pressure. (Both have stiff sidewalls but for totally different reasons)


In my experience, you can go from an average performing OEM RTF to a Max or Extreme performance tire “of the same size” and improves steering response and delivers significant higher levels of grip.


The Michelin Pilot Super Sport is the highest ranking Max Performance Summer tire on the market, 2nd is the Bridgestone S-04 (according to tire rack reviews). I run S-04’s because my local Firestone/Bridgestone dealer has exceptional service and the local Michelin dealer does not.


The tradeoffs, if you get a flat you are on the side of the road so I would strongly suggest having an air pump and plug kit without RFT’s. The plus side, you can repair a non RTF if you want but most dealers will not repair a RFT forcing you to buy a new tire ( if you don’t have road hazard).

 

That depends on what you define as "go kart feel".
If skipping off the tarmac surface over bumps due to stiff and poorly sticking RFT tires is it - yes - you will no longer be able to under-steer-bump off the road. One of my biggest initial disappointments with the MCS was excessive bump steer whenever you hit a road imperfection while accelerating out of a turn. The front end would break traction in a flash over smallest bumps.

After ditching RFTs for proper summer performance tires (first Bridgestone RE11s, now Hankook RS3's) the bump steer is almost completely gone!

Firstly, because the tires stick better - there are no high-end performance tiers in RFT trim.
Secondly, because more compliant sidewalls do a proper job of absorbing road imperfections w/out loosing traction.

No - you will not roll-over the sidewall and dismount your tires, as long as they are properly inflated.
About 38psi hot (after few autoX runs) works best for me. Any more and you start sacrificing traction for "RFT bump feel", and end up going slower.

a

P.S.: Michelin PSS's seam to need more pressure: ~45psi when autoX-ed my E90 335i. But I only ran once as the E90 is way too heavy and not nearly as quick as MCS. Haven't tried PSS's on the MCS yet.