Those MSM wheels weren't just fairly heavy, they were also fragile and expensive. A great combo :)
You really have to take the tire into account. I used to have a set of 17" OZ wheels with a Kumho AST on them and a set of 14" stock "daisy" wheels with Falken 215s on them. The 17" rode much better despite the smaller sidewall and increased weight because those old Falkens might as well have been filled with concrete.
Keith Tanner said:For all the love of Advanti Storms - they're out of production. If you want some and they're still available in your size, grab them ASAP.
Damn, can't do that this year for sure 
@Kieth, 80% of my Miata experience is with NA Miatas and being a "vintage" car guy I like the tall sidewall 14" combo. I'm aware it isn't the best thing for lap times. I also am a typical club racer.............why would I spend money improving a street car, that's just silly.
Everyone keeps saying “don’t forget tire weight”. Why? You can’t control the weight of the tire, and is there really THAT much of a difference between brands of the same size, same performance tires?
falken rt615k vs. Dunlop direzza star spec 2 blah blah blahs, what’s the difference in 205/50r15?
I can only speak for myself on tire weight but I'm always comparing the difference as it relates to different sizes. In my case it's particularly relevant because I run such a low powered car.
With that said I had considered going back to radials (currently on vintage Hoosier bias ply) but between the extra 4lbs per tire (same size) and the Hoosier guy telling me to stick with the vintage tires I haven't changed over.
A large portion of my thought process on this subject is colored by my having raced 125cc GP bikes before switching to cars. Doing things like running a slightly narrower tire, smaller chain and the like because it cuts down on rolling resistance all in search of an extra 50 rpm.
Going up 10mm on tire width on my Subaru Outback has cost a consistent 1.8 MPG. The only reason I did this is I had to get tires that day (long story), normally I would have waited for the exact size............the extra $7.50 a month for gasoline eats at me not to mention the extra 1.5hp the wider tires are eating up.
So back to the original topic; Will you notice? Yes. Will it matter? Probably not.
_ said:Everyone keeps saying “don’t forget tire weight”. Why? You can’t control the weight of the tire, and is there really THAT much of a difference between brands of the same size, same performance tires?
falken rt615k vs. Dunlop direzza star spec 2 blah blah blahs, what’s the difference in 205/50r15?
Don't forget the tire construction, that's more important than the weight. Sidewall stiffness, tread compound, tread pattern - all that is more obvious than 3 lbs on the wheel.
If you want to see tire weights, go to Tire Rack and click on Specs. For Miata-style tires they don't vary a lot, but if you get into light truck or offroad tires with 4-10 ply sidewalls there can be massive differences.
You can reach out to Marc at Planet Miata. He's parted a huge amount of NA & NB cars for racing purposes and I bought two sets of super light hollow spoke 14" wheels this year.
I'm sure he has 15" OEM and probably some aftermarket stuff as well. Prices were fantastic and he's a good guy to race against...
He preps and races SM cars so he might not be there, but someone should get back to you soon. He'll quote a delivered price so just let him know where you are.
He may also have some Spec Miata wheels - 15x7, right around 12.5 lbs if memory serves.
Thanks folks. What are the spec Miata wheels? Are they a certain brand?
FWIW, I weighed my stock wheel/tire and then my 6ul/RE-71 combo. Seems like the 15x8 6uls with Re-71s were a little less than 5lbs heavier which coincidentally is about what a FM little big brake kit saves :) It's on my want list.
A Toyo RA1 weighed a couple of pounds more than the short lived Goodyear radial R compound. That combined with going to Slipstreams from factory 15's was night and day. Again, this was on a rough track. I didn't pick up speed down the straights that couldn't be explained away by increased cornering speed.
_ said:Thanks folks. What are the spec Miata wheels? Are they a certain brand?
No, they just have to meet a certain dimension and minimum weight. There are a whole bunch of cheap 15x7s that are right at that weight.
In reply to _ :
Spec Miata wheels per the SCCA GCR rules are 15" 15x7 and must weight at least 13 lbs. Most will weigh 13.2-13.4.
The stock NB 15" wheel are 15x6.5 and weight was about 12 lbs but I can't remember if it was 12.5 or closer to 12. It's a fantastic stock wheel and I just sold a really nice set locally in Michigan for $150 to an autocross friend of mine.
In reply to fornetti14 :
I’ve been looking for one of these. I have the 14” version of that wheel. And I’m shocked that it grew and didn’t really add much weight. Sadly, they don’t exist in my area.
fornetti14 said:In reply to _ :
Spec Miata wheels per the SCCA GCR rules are 15" 15x7 and must weight at least 13 lbs. Most will weigh 13.2-13.4.
The stock NB 15" wheel are 15x6.5 and weight was about 12 lbs but I can't remember if it was 12.5 or closer to 12. It's a fantastic stock wheel and I just sold a really nice set locally in Michigan for $150 to an autocross friend of mine.
Isn't the nb1s 15x6, and nb2s 16x6.5s?
Not that this is apples to apples, but my Mazda B4000 went from 31/10.5-15 to 265/75-16 (adding 1" of overall diameter and about 8 lbs per unit) and I didn't notice any difference.... with the whopping 160 hp/225 tq from the wheezer-era 4.0L.
You will notice some dynamics change in a lighter, modestly-powered car. The big part isn't the 3 lbs, it is where the 3 lbs IS. When you go with bigger wheels and lower profile tires, you are placing the greater mass toward the outside of the circumference. Acceleration will suffer (not sure if you'll notice) and other dynamics will change slightly.
Also be aware of limit handling. As you increase wheel diameter and decrease sidewall height, tires become less forgiving. 185/60-14s are ridiculously forgiving. As you approach a limit, they start to complain, but you still have a long way to go before they just put you in a ditch. As the sidewalls get shorter, the difference between grip and slip can become a pretty cut-and-dried line.
My Impala SS came with 17"s and 255/50s. I traded something for a set of 20"s with 285/30s. It didn't take many butt-puckering uncontrolled tail-outs before I went back to 17s. It all has to do with the camber curve, overall traction coefficient, and weight of the vehicle. I personally would skip the 16s and focus on 15s.
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