325/30 R21 Tires

The following tires have been reviewed in 325/30 R21.

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Tire Reviewed Dry Grip Wet Grip Feedback Handling Wear Comfort
Dynamo HISCEND H MSU01 (6) 98% 95% 97% 97% 88% 93%
Michelin Pilot Sport Cup 2 R (2) 100% 20% 100% 100% 100% 100%
Continental WinterContact TS 850 (56) 88% 90% 85% 85% 85% 90%
Accelera Iota ST68 (18) 84% 78% 69% 69% 77% 74%

325/30 21 Tire Review Highlights

Accelera Iota ST68 rated 83% while driving a BMW X5
Driving on mostly country roads for 10000 spirited miles
Surprised at the quality of these cheap tires. Bought other cheap tires for other cars and generally you get what you pay for but these are good but they don't last long
tire reviewed on 2024-09-11 18:32:33
Dynamo HISCEND H MSU01 rated 91% while driving a Porsche 911 3.0
Driving on a combination of roads for 15000 spirited miles
Great looking tires, very good on the road, quiet and grippy. Handle well on cornering in dry and wet. I’ve put them to the test with some hard driving and they haven’t let me down. A surprisingly good price too. Only thing after 15000 miles they’re about half worn. Will rotate and hopefully get another 15000 miles.
tire reviewed on 2022-03-08 14:33:02
Continental WinterContact TS 850 rated 76% while driving a BMW X5 3.0d Sport
Driving on mostly country roads for 20000 spirited miles
Jonathan kindly replied to an Email enquiry. From his reply, I went ahead and placed 21 inch run-flat Continental WinterContacts on to my 2017 X5, that has different tire sizes, from front to back. The wife loved the difference to her feeling of safety they made, between the Scottish Highlands Cold Winter and the wet/cold Autumn/Spring of Herefordshire England, 'so much so', she disliked the stock tires being replaced back on the wheels for the summer and instantly felt less safe. This was due to a perception feeling of no longer being stuck to the tarmac with the stock summer tires, as compared to the Continentals. They have served us for 2 Autumns, Winters and Spring seasons very well and still in good condition. From Jonathan's most recent youtube videos, Im inclining towards Michelin UHP all season 4 tires, as the twice yearly tire change with the reality of UK Weather, be it Scotland of England my wife and I find ourselves, Jonathan's informative video's lead all, or certainly myself, towards all season tires from now onwards, especially with the advances in tire technology we are seeing with the Michelin and Continental brands. Changing vehicles this Sept from X5 40d 2017 model to X3 M40i 2021 model with 21 inch run-flat wheels. My biggest issue with tire change, is BMW dealerships don't or will not put new winter tires on 21 inch wheels, so you have to go to an independent tire business, that more often than not, has to order in the tires required for 21 inch runflat type wheels. Another reasons for my decision with a new vehicle, a new tire solution to all season tires (Note: at 21 inch run-flats, there are not many tire manufactures to choose between, though improving slightly each year) These Continental WinterContact tires have been amazing and made us watch motorist abandon, struggle, or slip off roads in snow conditions, as we quickly drove between destinations with full safety and trust in the tires. Even in wet and dry, as a normal driver (No Track) these tires kept us glued to the road in wet and dry conditions, until real warm weather made us change back to stock summer tires. But, the UK weather of recent, is so inter-changeble, both in Scotland and England, that the 7 degree point to change winter/summer is blurred often right through Autumn, Winter and Spring. Today 2021, early May in Scotland I'm driving with snow on the road. Thankfully we have kept the winter tires on even later this year!
tire reviewed on 2021-05-06 21:04:07
Dunlop Sport Maxx Race 2 rated 0% while driving a Porsche 991.1 GT3 RS
Driving on track for 1000 spirited miles
Early review. I actually think that I like these better than the MPCS2. I'm surprised cos I thought that it would be a 50/50 split. The Dunnies definitely seem grippier in the dry and therefore inspire more confidence to brake very late and dive bomb those corners. The dry grip is superb. If they last as long as the Michies or even almost as long and have acceptable wet grip then I am a new convert. I really don't care about comfort !
tire reviewed on 2019-03-09 19:30:15
Michelin Pilot Sport Cup 2 R rated 0% while driving a Porsche 991.1 GT3 RS
Driving on track for 350 spirited miles
Dry Grip 10/10
I had a chance to get a set of Pilot Sport Cup 2 R N0 on 991.1 GT3 RS and drove it on the Nordschleife. It looks like the Corvette Spec'd PSC2 ZP (i.e. shaved and more aggressively patterned PSC2), although this one is not a runflat tire. Anyway, it has a tremendous amount of grip and gives you extremely planted feeling. There are no other street tires feel like this one. Granted, I've used only two tires on the ring with this car, but they are Trofeo R and PSC2 N2. But this is a mile better than PSC2 N2 and maybe a half mile better than Trofeo R, which puts this tire on par with real slick tires.

These planted feeling is extremely important when you're on the Nordschleife, because it is very scary track (due to its bumpiness and unforgiving layouts) and this scariness acts as the biggest limiting factor on your laptime (well at least for me). Thanks to its tremendous grip, I was able to reach 7:12 BTG with this tire (and 7:10 composite lap) within 9 TF laps (3 laps in a row, break, repeat). Conditions on that day (surface/air temp, traffic) was very good but it was so big improvement over my previous personal best BTG time with this car, which was 7:19 (with Trofeo R).

Consistency and resistance to the heat build up is pretty similar to regular PSC2, which is very good. Warm up speed is not on par with very fast tire but it’s okay.

Wet Grip 1/10
Well, the regular PSC2 was never a good tire on a fully wet track or highway. Typically, the high performance summer street tires are the best on this regards, and these sorts of tires (streetable track) are much worse than them (in every aspects, including grip, resistance to hydroplaning, etc), especially if it's actually raining.

However, PSC2 was more resistant to hydroplaning, compare to the regular streetable track tires or its previous gens (PSC+ and PSC), thanks to its much deeper and wider groove. It wasn't exactly on par with the high performance street tires but you have no problem following the regular traffic, even if it's raining heavily (hence standing water here and there), as it has similar resistance to hydroplaning with low performance comfy tires.

PSC2 R reverts back every improvement in this respect and make it worse. Now, it's basically one of the worst tire you can have, if the surface is anything wetter than slightly moist. If it's raining heavily and there are many pools of water on the road, you will have hard time to keep up with trucks, let alone the fast cars. I can't believe this tire is street legal, for both dry and wet performance.

Road Feedback N/A
If it means reading every uneven surface through the tire and steering system, I can't really say about this one, because 991 has an electric power steering and every EPS-equipped cars do not have same level of road feedback that is available on hydraulic systems.

Handling 10/10
Well. I don't care about wet performance, so I'll go with dry grip on this one.

Wear N/A
I only drove it for 9 laps on Nordschleife (about 3 of them were either warm-up or cooling laps) and a few hundred km on Autobahn. It wasn't enough to wear it out completely, hence I can't really say about its tread life or heat cycles. However, the tread on this one looks pretty much like shaved PSC2, so I don't expect it to last as long as the regular PSC2 does.

Comfort 5/10
I'm pretty dull at this area, because all of my cars have had these sort of tires for the last decade or so, thus I became very insensitive about the noise and comfort long ago. I guess it's about an average among these sort of tires because it didn't feel particularly harsh. But again, I'm not sure as I don't care at all.

Buy again 7/10 (if price goes down somewhat similar to regular PSC2, 10/10)
I'm not sure about its longevity, so I'm also not sure about the running cost. But if it's close to half of regular PSC2, shorter lifespan combined with greater purchase price will push the running cost significantly higher, and that is beyond I'm willing to pay (I've gone through 15-20 sets of tires per year usually). However, I'm willing to pay somewhat more at least once in a while, since it felt so good. If I have an unlimited budget, I'll probably always use this tire, but then again, if I have an unlimited budget, I would have a 911 RSR not GT3 RS.
tire reviewed on 2018-11-20 05:45:09
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