Hagerty.com

Your Miata is using the wrong tires, according to Mazda and Bridgestone

If you drive a first-generation Miata today, chances are you’ve never experienced it on original 14-inch tires. And that, says Mazda, means you’ve never really experienced it at all.


This is a companion discussion topic for the original entry at https://www.hagerty.com/articles-videos/articles/2019/04/03/mazda-and-bridgestone-original-spec-tires
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Great story. I’ve never understood how “experts” know more than the manufacturer and start swapping out wheels and tires. I remember my first ride in the then brand-new Miata. It was a transformative experience. Really a special car.

I can believe tires are the most engineered part of a car, swapping tires makes a huge difference in the way a car performs or fails to perform and anyone that has ever put race rubber on their daily driver can tell you what an instantly noticeable difference it makes in braking, handling is the second thing you notice.:grinning:

At a show a goodly number of years ago, I parked my '73 Volvo 1800ES right next to an early Porsche 911. After I took a picture of my car reflected in his hubcaps, I commented to the owner that he didn’t have the correct sized rubber on his car. His retort was that neither did I - I had to smile that we both knew the other car should have 185/70 tires mounted while we both had 195/65 rubber. It would be nice to know if similar tire development was done to the rare 185/70 tires currently available at similar prices.

Same deal with Datsun 240Z and 260Z. 14" OEM tires. Hard to find anything in that size. Looks like the best solutions are to go either with 15 or 16" rims and tires. Even with what can be available for 14" tires the profile (?aspect ratio?) makes for a tire that doesn’t look right (not filling the wheel wells) as the OEM spec did.

Keith had it right, many of the early adopters of the Miata called those tires Bridgerocks. In the rain it was like driving on snow. After a couple of Miatas with those tires I started changing to better rubber as soon as I bought the cars.

My most recent Miata (the 36th I’ve owned), a '16 ND Club got new wheels and tires after a few thousand miles.

The new Bridgestones might be fine for a collector of early NA Miatas but I won’t be pining for a set, especially at $1,000 a set.

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Because suspension setup is always a compromise, and the compromises chosen by the manufacturer may not match up to what the owner wants. The SF-325 rode well and was light, but it had softer responses and lower grip than a lot of owners were looking for, especially those that were competing with the car. The same is true today, the OE tire choice may or may not be right for the owner.

The full quote from my chat with David - a full year ago! - is as follows:
“…they weren’t a great tire. We used to call them “Bridgerocks” and tire technology has really moved on in nearly 3 decades.”

It’s worth noting that Mazda and Bridgestone agreed, as they updated the technology of the reissue.
Keith Tanner, Flyin’ Miata

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When I bought my 95 in 2002, the original tires were long gone. The biggest problem is the lack of tires available in 14" Its important to remember that low unsprung weight is critical on the Miata. The big wheels so popular today don’t belong on the early examples.

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Important context from Mr. Tanner, who has literally written the book on Miata tuning.

And I should note that, provocative headline aside, my takeaway from talking to Mazda and Bridgestone engineers is not that these reproduction tires are the only authentic way to experience a Miata. Rather, they helped me think about how important tires are to a car’s behavior and feel, even if it’s not hitting a race track.

This is why I continue to run 14" wheels for my '75 Ferrari 308. The ride is so smooth and handling is still great (for a car that is used almost entirely on the street, which, as pointed out, should be kept into consideration). People shouldn’t complain about the price for these Miata tires, as the cost for the 308’s Michelin XWX is nearly three times that!

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Finding the “correct” tires for older cars like my 1985 Toyota Celica Supra is quite a problem. Coker has repop Radial T/A’s, but they’re only rated to 112MPH. Probably moot as I doubt I’ll ever drive the car that fast.

I went with the ‘restomod’ look, and replaced the 14x7 wheels with 16x8, and put some ‘modern’ tires on the car.

  • Jim

I bought my '97 Miata in '98 with 13k miles and the original Bridgestones on it. Even then, they were not great in the rain (or dry). By 20k miles they were dangerous in the rain. I replaced them with Bridgestone RE-71s and turned a great sportscar into a brilliant one!

A couple of years ago, I had a set of Dunlop Direzza ZII Star Specs put on the car and the light, quick handling that I had experienced with the old RE-71s was back.

I love the Miata with 14" tires, but would never consider putting SF-325s on it.

SOLUTION?!?..Buy A CORVETTE!!! :slight_smile:

Buy a Corvette ?!? These are two totally different kinds of cars. I’ll admit that stomping on the gas as a red light turns green and getting to the next red light many seconds ahead of everyone else is fun in a way, but try going around a twisting back-road in the country in a Corvette, then try it in a Miata. Corvettes are for power, Miatas are for people who love to drive.
I have driven Corvettes, but I have OWNED a Miata for 15 years, and I will never sell it.

I’d love to have an updated SF325 as an option for my Miata. Yes I was not that impressed with them when my car was new 30 years ago but these new ones sound like they are better and 14” tires of any sort are getting hard to find. I just had one of my 4-year-old BFGs get damaged by a road hazard and opted for a NOS 4-year-old BFG over putting a new set of inferior tires on the car. When the BFGs wear out I’d gladly consider these Bridgestones even at $1000 a set.

As a drift nerd who started with driving miatas, hearing that the car’s engineers didn’t intend for it to be a grip monster is a hilarious and unexpected bit of validation for all my years of driving slippery miatas.