ND 17" tyres. Would like NickD's opinion

Technical Area Wheels, Tyres & Brakes
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Been a while since anybody asked this question on here. Could ask NickD by PM but if I ask here then it might be useful to plenty of others.

So a bit of my history first. My previous MX-5, a 2.0 NC Sport had original equipment Continentals (205/45/17) when I bought it. Nothing wrong with them but after taking NickD’s advice I had him fit a set of Kumho KU39s. They were amazing. The car felt so much better and more predictable and I had complete confidence in them in all conditions. Great on wear and were still on the car with plenty of tread 10k miles later when I sold it.

Fast forward to now and I’m in a ND1 2.0 Sport with the same size 205/45/17 Bridgestones. Car is now 4 years old with 17k on the clock. Front pair are original with 3mm of tread left and the rears were replaced by the previous owner 6k ago and have 5mm tread.

I’ve nothing in particular against the Bridgestones but on occasions I’ve had minor loss of rear grip if I’ve lit them up a bit on setting off. I felt happier with the KU39s on the NC than the Bridgestones on the ND. I’d go for them again but they are no longer available in this size.

My friendly Mazda dealer who did my service and MOT yesterday offered a replacement pair of Bridgestones again for £152.40 each. A quick search shows that’s not exactly a bargain. I can find the same thing locally at £105.70 each.

I’m not a brand snob and don’t want to pay over the odds just to get a well known name but I don’t want to skimp on quality. I’m not intending to go on track but use the car all year round. I’m retired now so if there’s a lot of ice or snow I’ll use the FWD Juke. On the other hand I’m not going to stop using it just in case it rains while I’m out.

So here’s what I want. Something at least as good as the Bridgestone S001 in 205/45/17. Preferably better.

I don’t need ultimate performance in the dry as I never really push it but want great performance in the wet.

I want predictable handling and don’t want something that suddenly lets go on the limits.

I’d like a bit better wear than the Bridgestones have given, the KU39s were certainly better.

My current thinking is that Kumho PS71s will fit the bill. Nick has recommended them in the past but wondered if experience has changes his view now they have been on the market a bit longer. I can have a set of 4 PS71s fitted for less than a pair of Bridgestones at my Mazda dealer.

So - Question 1. Will I be suitably impressed if I swap to the PS71 as I was with the KU39.

Question 2. Is there anything significantly better without paying a small fortune.

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I have the ps71’s recommended by Nick and I have found them to be an excellent choice. They are really good in the wet and have not broke away on me yet something the Bridgestones did to me often. Now its turned colder I’ve also noticed they are much quieter than the Bridgestones much less crashy. Be warned though they take a while to break in. I was very unsure of these Khumos when they were first on the car and it took a few weeks for them to come good. so take it easy for a while but after that they do the Business especially in the wet. Hopefully they will handle a little snow something the Bridgestones could never do. I found them lethal even with just a few flakes on the road.I wont hesitate to buy the ps71’s again personally .

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Better is hugely subjective and influenced by an almost endless list of personal choices, prejudices and experiences. A tyre that has a nail stuck in it but didn’t go down can be described as better than one that did, even though the outcome was total chance. 

PS71 will do everything most MX-5 drivers want totally adequately. There are those that believe you have to spend far more because that must be better. 

The KU39 is still currently available in 215 45 17 as well and would work out at ÂŁ300 a set delivered. PS71 would be ÂŁ288

A RainSport3, which undoubtedly has good wet weather performance, but is not the longest lived tyre on the planet would be £336 delivered and…

Conti EcoContact6 would be ÂŁ446.

 

You pays your money etc…  

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I have Bridgestones on my daily driver, a FWD Seat hatchback, can’t wait to get rid of them but I can’t seem to wear them out It’s on 22k miles now and still plenty of tread but age is upon them, they were on the car from new in 2014. If I do eventually change them (maybe the car will get part ex early next year) I would undoubtedly got for the Kumho, I have them on my Mk3 sport.

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Are the Kumhos on your Mk3 the KU39 or the PS71? I know the KU39s are good but wanted to confirm the PS71s are as highly regarded.

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They are the KU39’s, actually fitted by Nick 

I’ve followed other threads on tyres and the PS71 seem to be an equal to the previous tyre but obviously I have not experienced those on a car.

The only other one that seems to come up on forum’s is the Dunlop bluresponse, I do believe those are as I term a premium tyre??. As Nick says it’s an often talked about subject with everyone having their favourite/experience with tyres. If I’m buying tyres again it wouldn’t be Bridgestone, nor Avon’s, the latter were on my Mk3 Sport before the Kumho but to be fair they were past their useable life.

 

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Not going to rush into it. Still got 3mm on the front and 5mm on the back so will wait until the fronts are approaching the 2mm mark and then go for a set of four. May be throwing a bit of tread on the back ones but don’t like mixing brands.

Interesting to see that in the 205/45/17 size the PS71 is A rated for wet grip and C for fuel efficiency. The S001 Potenza is B and E. I do know that this isn’t any indication of whether they suit the car though. Looking at an online review site that shows the car type the PS71 has good feedback from other MX-5 owners.

Thanks all, particularly NickD for your input.

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Here is my view on it. You are procrastinating on which tyres are better than others while you are running around on tyres you don’t like and have “loss of grip.” 

You are going to spend the money in the end, just do it. I have had people phone me before and say "I called you 9 months ago about tyres, I was actually going to come to you this week but crashed and wrote the car off. 

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The MX-5 is my first and only experience of Bridgestones, I like many others it seems have not been a fan of them. I’ll be switching to Goodyear Eagle F1s when the time comes (not till next year). 

I’ve run the Goodyears before on a Clio Sport 172 and found them to be excellent tyres, amongst performance benefits they also were one of the quietest tyres on the market (similar to Dunlop) but a significant improvement over Continentals which I had as standard previously on Mercedes and hated. 

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As recounted in another thread I faced the same dilemma . My ND’s Bridgestones were fine (but not brilliant ) until some buttock tightening action in the wet , still with plenty of tread left. I researched alternatives ( ie noodled around on google a bit ) and the consensus of many tests seemed to be that Michelin PS4 were outstanding in dry and wet . And so they they have turned out to be . No idea what the Kumhos are like but found the brand excellent on cars as varied as a Yeti and as 'touring tyres ’ on a Seven .

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Fully get what you are saying but here’s what I said in my first post.

I’ve nothing in particular against the Bridgestones but on occasions I’ve had minor loss of rear grip if I’ve lit them up a bit on setting off.

The only times the tyres have had less than perfect contact with the road are if I’ve given it too many revs and dropped the clutch too quick.

I’ve only done just under 3k miles in the last year and around 1200 of those were in the past month on a trip from Lincoln to Devon and a week of touring while I was there. I’m unlikely to do more than a thousand miles before next spring.

My wife and I are now both retired and it’s rare that both cars are in use at the same time. If it’s a nice day I’ll go out in the 5. If it’s raining and I’m popping around the shops I’ll go in the Juke. That’s the car that we use if we need to be somewhere whatever the weather. It’s got Uniroyal Rainsports all round on 18" wheels and they are great in all weather. They have also worn very well but the car doesn’t really have the power to blow the skin off a rice pudding so that probably helps.

I’m aware from various test results that tyre performance drops off with wear but in reality it’s only wet grip and stopping distance that are affected. In the dry slicks are best. There’s no appreciable difference between a new tyre with 7-8mm and one with 3mm of tread. Once you get below 3mm wet grip goes off. From various graphs including ROSPA tests the change from 3mm to 2mm and from 2mm to 1.6mm seem around the same. If I change tyres at 2mm I’ll have got around 20% more life out of them than if I change at 3mm. I do not intend to go right down to the 1.6mm.

I would guess that an A or B rated wet grip tyre be it Uniroyal, Kumho, Bridgestone or similar will still be better at 2mm than many of the budget brands when new.

I’ve never been the sort of driver that pushes the car whatever the conditions. The 3mm fronts will take me through to the spring without getting down to 2mm and I’ll change them before I get caught in any April showers. If there’s ice or snow it won’t be moving off the drive. The rears will probably still be at around 4mm but I’ll change the full set anyway.

I love the way the car drives on the Bridgestones but then I loved the way my NC drove on the Continentals. I just loved it even more on the Kumhos.

Hopefully I’ll be as happy with the PS71s as the KU39s.

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Oh for pity’s sake don’t try to save 10 p by driving your tyres down to 2mm. Whatever ROSPA say. worn out tyres will work ok in the dry but at some point will try to kill you in the wet . No matter how premium the tyre , if it has legal , but little , tread it’ll aquaplane like buggery the first time you hit standing water . You may then have a short time to reflect on the old proverb about losing a ship for a ha’porth of tar …

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Here’s the dealer report on the tyres

          Outer     Middle    Inner     Wear

NSF     3.8mm   4.0mm   3.0mm   78%

OSF     4.4mm   4.5mm   3.2mm   75%

OSR     5.3mm   5.5mm   5.0mm   47%

NSR      5.2mm   5.6mm   5.2mm   44%

Still plenty of meat on all of them apart from the inners at the front. Even if I keep going until the NSF is down to 2mm I’ll still probably have over 3mm across the 75% figure on both fronts. If it was 3mm right across both fronts I’d be thinking along the same lines as you. Tons left on the back ones that I don’t want to throw away and I don’t want mixed tyres.

At this time of year it’s very much a fair weather car, not planning any big trips anyway.

Come spring I’ll get a set of four, probably Kumho, and I’ll get the alignment checked too.

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Just keep justifying your decision.

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Some quantitative (rather than anecdotal) results:
[color=red]Auto Bild 2019 Summer tyre test[/color]
Kumho PS71 came 20th (out of 20). Michelin Pilot Sport 4 came 1st.
Guess which I bought!

1 Like
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Buy what tyre you like but these “official” tests continue to frustrate.

As someone who had done a significant amount of track tyre testing I can state for a fact that a tyre will perform differently on a different car. It will perform differently on a different track. It will perform differently on the same track on a different car, on a different day with just a change of temperature and will perform differently on the came car on the same track on just a different day. 

So to start with these tests are not conducted on an MX-5 it will be in 99% of cases on a front heavy Golf. It is not the same tyre size which again will make a significant difference, probably using a different type of car for different tests and since there are 20 tyres on test here is is exceptionally unlikely that the tests were performed on the same car, even on the same day and with the same driver. Even if they had the financial resource to have had the ability to have 20 identical cars and 20 drivers it would still take well over a day to conduct all of these time consuming tests. As this is a magazine they will have had to borrow cars, beg tyres and test track time. Even getting 5 identical cars would be a task. Changing tyres and conducting tests will take vast amounts of time. How long does it take to get 20 sets of tyres round a test track to conduct a dry handling test? How long does it take to run a new tyre in before the test? How many times do you have to repeat a test to get a reliable result. We struggle to test just 3 tyres in a day and we are generally only looking at outright lap time. How long does it take to change tyres and get out there again? Was it the same driver, the same day, the same weather, temperature and so on and so on. We’re all the brake pad performance the same?  If they were performed on the same car what was the wear and performance like on the first stop to the 60th stop? What is the influence of advertising money on the results? How much is just made up because they ran out of time or messed up the results? More importantly where are the drivers feelings and experiences of how the tyre felt whan they were driving, how they communicated on the limit and the feed back they gave? Having worked on several car launches this year a number of high performing brands suffer very quickly when pushed hard with shoulders wearing out in very few miles.

Sometimes anecdotal evidence is more than good enough.

The next magazine or the same magazine next year will have the same tyres with different results. 

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Thanks Fred for the interesting reading and thanks Nick for the very interesting insight into testing.

Nick has highlighted why I was looking for tyres that suit the 5 rather than just good tyres.

Investigating the tests further the car used was a BMW 1 Series. Probably the latest model which is FWD. Certainly very dissimilar to the 5.

Even if you take the test results as gospel they initially tested 53 tyres and then did full tests on the best 20 so the Kumho at 20th didn’t disgrace itself. There’s only around 10% difference in wet and dry stopping distances between No1 and No20. All 20 tested were either “Highly Recommended”, “Recommended” or “Conditionally Recommended”. 

The fact that the PS71 scored so badly in wear makes me think again. I’m aware that Nick says the Rainsport 3 isn’t the longest lived tyre but they have performed really well and lasted on our Juke. I’ll investigate those and the Conti EcoContact6 that Nick initially recommended. It’s a shame neither featured in that test even if it was just for the wear figures.

One other factor that I do want to keep in mind is easy availability. I had an unrepairable puncture while touring in my NC. Did around 1,000 miles on three Kumhos and a Hankook before I got back to a matched set. Paying out for a “get you home” tyre isn’t much fun.

 

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Oh, and the fact that a set of 215/45R17 Michelin PS4s was ÂŁ356 fitted and balanced (and Nitrogen filled!) from my local ATS.

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And Nitrogen does what for you? 

I have just thrown a bag of green caps away.Â