I'm considering (reluctantly) parting with my 2003 MC, and have been looking at either another MC or an MCS.

Options are pricey, and I seem to want all of them.

That said, what do 17" wheels generally give you compared to 16"?

How do they affect, handling, ride, agility?

My current model (sport package) has the 16" star spoke wheels w runflats.

 

More unsprung weight and a rougher ride.

17" wheels will give you a little crisper turn-in, given the same tires. However, this varies a lot with different tires.

My recommendation is to get the cheapest factory tires with the car. Use them for snow tires, or sell them on the NAM Marketplace. I sold my 17" Crown Spokes there. Then, for less than the upgrade price to 17" factory wheels, get a set of lightweight 16x7, or if you prefer, 17x7 aftermarket wheels. They will look as good or better than the factory wheels, and can be much lighter for better handling, braking, acceleration, and ride comfort.

 

less sidewall (i.e. 17") makes a big difference in ride quality, and there is an apparent correlation between wheel diameter and "mushrooming" at the shock towers.

i'd strongly recommend a nice set of 16" rims for less weight and more fun

i run 15" (but that's an autocross choice, not street primarily)

i just changed from a 225/45 [RS2] to a 195/55 [Z1] without loss of performance, and the increase in sidewall height from 2.5 to 3.25" transformed the car from borderline irritating to smooth and quiet. i wouldn't touch a /40 ratio tire with a ten foot pole -- there just isn't any shock absorbtion left with such a low profile.

mind you i'm running coil overs, to my chassis is a fair bit stiffer than stock

less diameter will increase performance directly, as the difference between a 25" and a 24" is 4% which translates into a 4% increase in thrust at the contact patch for a constant torque at the axle - in other words it has the same effect as a 4% torque boost at the flywheel

note the "revs/mile" stat for tires in varying sizes - I like 890 or more

YMMV

 

really? Granted, I'm no expert, which is why I am asking, but I was under the impression that bigger wheels were better (to an extent), more grip and such, until the extra weight ends up hurting you at the ridiculous sizes. so wouldn't 17s be better, performance wise than 16s, or is this pretty much all personal preference? maybe this is what was meant by "more fun" less grip would make it easier to slide correct? forgive my uneducated rantings, but i am trying to figure things out as well.

 

not necessarily. The weight of the wheel is secondary to the weight of the tire, due to the tire's position. You have to compare the mounted set - sometimes tire weights vary quite a bit between sizes, even with the same models.

example - on my wife's FX35, I had 265/60/18 Avon tires on forged 18.2lb wheels. The tires weighed 45lbs! so, 63lbs or so mounted. She hated the wheels, so I went back to a 20"....265/50/20, same Avon tire model. This one weighed 38lbs and the wheels weighed 25lbs. Net difference in unsprung weight = NONE. Further, she noted better handling and a smoother ride (this is counterintuitive). The only thing I can explain about the ride is diff tire construction in the 20" size and/or the lower weight of the tire at the very outside of the rolling diameter.

My experience with the MINI is that there's a balance between size/weight/handling/ride. For MC's....16's. For MCS's....17. The MC benefits most from the lowest weight since torque is so low.

I've never noticed a performance difference on my car with 10lb forged 15's or 24lb cast 18's. They feel different, but not in a ZOMG THIS SUCKS kind of way. The biggest difference was in tires. If you go with a 15"....get a stiff performance tire...you have plenty of sidewall still but if you get a wimpy, soft tire (SPT or DZ101 for ex), it will ride great but have no turn-in to speak of.

 

Your example can't be from a MINI. You aren't going to see much tire weight difference on the MINI unless you change tire width or dia.

Dunlop SP Sport 01 DSST (runflat):
205/45ZR17.........22 lbs.......24.5" O.D. (came stock on my MCS)
205/40ZR18.........21 lbs.......24.4: O.D.
Not available in 16"

Michelin Pilot Exalto PE2 (non-runflat):
205/50ZR16.........20 lbs.......24.1" O.D.
205/45ZR17.........20 lbs.......24.3" O.D.
225/40ZR18.........23 lbs.......25.0" O.D. (wider and large dia. tire)

Pirelli PZero Nero M&S (non-runflat):
205/55ZR16.........21 lbs........24.9" O.D.
205/50ZR16.........20 lbs........24.1" O.D.
205/45ZR17.........20 lbs........24.3" O.D.

In theory, weight that is farther out from the hub will have more effect on spinning inertia. So, the tread weight will have somewhat more effect on braking and acceleration than the weight in the wheel. However, they are not very far apart on a large wheel because the majority of wheel weight will be in the rim, and the sidewall can't be very high. This gives the smaller wheel the advantage because its weight is closer to the hub. It also makes wheel weight a bigger issue on the larger wheels. All the more reason not to go for they very heavy OEM 17" wheels.

For ride comfort, it is the total weight of the wheel/tire combination. So, wheel size wont matter if they all weight the same.

 

Another disadvantage of larger wheels is increased vulnerability to damage from potholes, due to less sidewall height.

Everything being a trade-off, I agree with those who recommend 16" wheels as the best compromise for both MC and MCS in terms of unsprung weight, ride, rim protection, grip, turn-in and aesthetics.

 

did the fact that I said 'my wife's FX35' clue you in?

I currently have 15's and 17's for my car. I've had 16's and 18's as well. In my opinion, 17 is the best compromise for looks, 16 the best for performance. Not to mention tire availability in MINI friendly sizes is best in 17"

 

Lighter is better.

 

Totally irrelevant comment. As was your example.

 

proving your blanket statement was not 100% accurate is irrelevant? And no, my example explains the point perfectly, albeit in more extreme amounts than applicable to a MINI. Just because I was right and you're wrong doesn't mean my comment is irrelevant. 404 Logic Not Found Error.

Yes, lighter is quicker to accelerate from a standstill but heavier is quicker to accelerate from speed. Newton wasn't wrong.

 

Besides looks. What if any advantages or disadavantages with 15" wheels? I've been running 16" and have been thinking of changing to 15.

 

tire sizes get funky. The proper one for the MINI isn't made unless you stick to OEM sizes (and what fun is that/??)

 

Best is to have different wheels/tires for different occasions. I have 15s for AutoX (extreme newbie here) and 18s for everyday driving and Mini club drives.

 

Hey PGT, are you saying that all other things being equal, cars with light tires will accelerate faster from a stop, while cars with heavy tiers will accelerate faster at speed?

If so, I don't get it. Newton said F = m a, then a = F / m. There is no component for "current speed" in the formula for acceleration.

 

most folks running 15" run them as winter rims, with winter rubber

i run them for autocross

the advantages are
- lower effective gear ratio
- lower cg
- less weight (but this varies on the wheel brand as noted earlier)
- less tire weight too

the disadvantages are
- lower ride height (this is a mixed bag, i have to be CAREFUL with the 15s)
- less fuel mileage (more revs/mile)
- fewer tires to choose from (this has been a pain for me over the winter)

all in all the pros outweigh the cons for me, and i settled for the Direzza Star Spec Z1 195/55-15 which seems to work really well.

some folks think the aesthetics of the 15" rims are poor as they do not fill the wheel wells, but im my case i'm down 1.5" anyway so there's no gap to catch the eye

if you are racing, you might ponder it - otherwise i'm with the "light 16"" crowd all the way - better tire selection and all round performance

 

What is the widest width you can go on MCS 2008?

 

no, but objects in motion tend to stay in motion. a light wheel has less flywheel effect than a heavy one.

 

Newton wasn't wrong, but you are.

Acceleration of a wheel is a function of applied torque and rotational inertia, and rotational inertia is fixed for any particular wheel/tire combo (it only depends on the weight of the wheel and tire and how that weight is distributed.)

So if you have two wheel/tire combos with different moments of inertia (either because of differing weight or differing geometry), the wheel with the smaller moment of inertia will *always* require less torque to accelerate it from one speed to a higher speed, whether the initial speed is zero or not.

 

Yes, but that just means that with a heavier flywheel (or heavier wheels) the car won't "coast down" as quickly when you let off the gas. It doesn't mean that the car with the heavier wheels (or flywheel) will accelerate more quickly from a running start.

 

if you're car is hovering in space, sure! Mine does in fact roll on pavement with high μ, therefore, μ of the road surface, drag from brakes, drivetrain etc must be figured in to the equation. The wheels/tires don't spin in a vacuum.

 

To the OP: I agree with Robin. I got 17" flamespokes for looks, and I like 'em a lot (RFs of course). But if I had it to do again I'd get the cheapo wheels/tires and go aftermarket. A wheel upgrade from Mini is $700 (or more) and you can get a nice set of wheels for less. Add some non-rf tires, sell the new OEMs and you could come out ahead.

 

I like the look of 18" wheels on a MCS... something very slick about that size. Anything larger starts to look a bit silly. I'm sure that there are some turn-in benefits to having a smaller wheel and a lightness issue that is being debated (if you call the physics rants above a debate) above as well.

I run 17"s on the street because the tires are a smidge less expensive than 18's. They do well on spirited drives and look pretty nice. I can also get a nice wide tire on them (215 instead of the factory 205) without any rubbing on a 40 or 45 series profile.

I just picked up some light 16" track wheels. They look a bit funny on my MCS with the aero sills and painted arches... it just looks like the car sits too low, but I'm used to seeing the 17s on there. They feel great, though, and turn-in beautifully.

I like the look of 15's on a MC... I'm a big fan of the Holeys. One downside of a smaller wheel is that you lose most of your brake kit options (Wilwoods, TSW, Brembo, DT, etc) when you go to a 15" wheel unless you put some thick spacers on there (if it's even possible). I have to use 15mm spacers on the fronts to get my 16" track wheels on over the smallest setup that Wilwood makes (11.75" rotor kit) for the MINI.

 

True, but unless you're talking about different cars or different tire compounds, things like friction between the tire and road, driveline losses, brake drag, etcetera are unchanged by simply swapping a heavy wheel/tire combo for a lighter one. (Technically, the frictional force on the car as a result of the μ between the tire and the road will be slightly higher for the car with heavier wheels, but that increase is small considering the overall weight of the car, and would only serve to make the car accelerate more slowly, not more quickly).

If you're using the same car and the same tread compound, going from a heavier wheel/tire combo to a lighter one will improve your acceleration both from a standing start *and* from a running start.

 

Your example was irrelevant because it doesn't apply to MINIs.

404 Logic Not Found Error.
Acceleration is increasing motion. Thehe heavier object will require more energy than the lighter object, regardless of initial speed. Return to Physics 101, do not pass GO, do not collect $200.