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Lotus Europa Forums => Garage => Topic started by: BDA on Thursday,March 01, 2018, 07:57:13 PM

Title: Another tire discussion
Post by: BDA on Thursday,March 01, 2018, 07:57:13 PM
Well, the Potenza RE-11A tires on the rear of my car are about 7000 miles old and about worn out. As I remember, when the car was new, front tires seemed to last forever but rear tires didn't last very long. That pattern is repeating but the rears lasted longer than this and I had hoped that new technology would yield better mileage.

So I'll soon be in the market for tires. I'm running 205/50-15 in the rear. I don't track or autocross my car but I would obviously like good grip at a reasonable price (around $100 or less) but I'd like to get better mileage from them, too. I've read some good reviews about Yokahama S Drive and KUMHO ECSTA PS31 also looks interesting.

Do any of you have any comments about either of these tires or have other suggestions?
Title: Re: Another tire discussion
Post by: EuropaTC on Thursday,March 01, 2018, 11:28:04 PM
In the UK market I'd guess that 7,000 is low but not unusual for performance tyres these days. I drive more like Miss Daisy than Lewis Hamilton and 9,000 seems to be the going rate for me with sporty tyres.  I think I was even below that with the MR2 Yokohamas, so 7,000 on a car like yours wouldn't strike me as bad.

Do you have the same tyre labelling that we've got over here ?  These days I just look for something with good wet weather performance and for my hobby car accept that I can't have good mileage and grip at the same time !  The bar chart labels are fairly recent here and for me they are helpful in sorting out between "grippy" and "ditchfinder" tyres

Labelling : http://www.etyres.co.uk/tyre-labelling/  (http://www.etyres.co.uk/tyre-labelling/)

The tyres I fitted last time on the Europa are these toyos. I'm sure they are better around but I've had a few versions of these and generally speaking I find their grip outlasts my nerve.....

http://www.etyres.co.uk/tyre-detail/toyo-proxes-t1-r-205-50-15-v/  (http://www.etyres.co.uk/tyre-detail/toyo-proxes-t1-r-205-50-15-v/)
Brian
Title: Re: Another tire discussion
Post by: Clifton on Friday,March 02, 2018, 04:52:28 AM
The RE-71 or BFG Rival-S would be comparable to what you have (soft).  They are the fastest. The Kumho V720 is a little harder/slower but still a 200TW. There is the Falken RT615 that will last longer but I doubt you'll be happy coming from the RE-11. A friend ran them for a month before going softer, this was just a street/weekend car. Many articles on Miata boards and in Grassroots Motorsports on all of them.
Title: Re: Another tire discussion
Post by: surfguitar58 on Friday,March 02, 2018, 05:28:37 AM
Since we’re talking about tires… I hate to be the overly enthusiastic newbie that asks obvious questions all the time, but:

1 – Does anyone know what brand and model tires came from the factory on the TCS with alloy rims, 175/70-13 up front and 185/70-13 rear?

2 – I’ve heard 205/60-13 rears and 185/60-13 fronts fit the standard 5.5 inch alloy rims and clear the fender well including lock-to-lock steering. Can anyone confirm or deny this? Looks like the 205/60s would result in a 2.5% speedometer exaggeration error.

3 – What is the tribe’s go-to street legal tire for performance driving. This will be a fair weather only car (though getting caught in the rain is unavoidable once in a while). I don’t have any racing aspirations but I’m not above aggressive sport driving when conditions permit, and want the car to handle at its best. I’m willing to pay a little more and live with shorter tire life to have tires that allow me to drive the car to its full potential occasionally. Thoughts?

Finally, I found this web site that does the best job I’ve seen yet at showing tire size variations, enjoy: https://www.rimsntires.com/specspro.jsp
Title: Re: Another tire discussion
Post by: BDA on Friday,March 02, 2018, 06:01:33 AM
First: Thanks, Clifton and Brian for your replies. I'm not able to respond to them just yet.

I don't remember the model, but my car came with Dunlops. They were not steel belted radials, maybe rayon belts.

IIRC, back when my car was new I put a rear wheel on the front and there was some minor scraping. That memory doesn't square with my current experience (I'm running 195/50-15s on the front with no scraping). I think you best bet is to find where your tire is closest to the body and measure how much room you have and compare that to your new tires.

If you end up with a different tire diameter, you can get your speedo adjusted. It involves counting the number of times your speedo cable turns over a defined distance and sending that number with the speedo to some place like Nisonger. Replacing your speedo with a GPS driven unit or a electronic unit is another option. Or you can live with an inaccurate speedo.
Title: Re: Another tire discussion
Post by: BDA on Friday,March 02, 2018, 09:18:35 AM
Brian,

EU or Brit tire performance codes are different from those in the US. The US has a UTQG (Universal Tire Quality Grade) system which compares wear rate, traction (actually wet traction) and temperature resistance (which is a sort of speed rating). Here's a link that describes the ratings and how they are arrived at: https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=48&s_kwcid=AL!3756!10!3780142791!30681728975&ef_id=WBtUSwAABQ7VlJd3:20180302154533:s

Unfortunately, the Toyo Proxes T1R are no longer available in 205/50-15 (at least they weren't listed on the retailers I checked and didn't see them on the Toyo website!).

Clifton,

Thanks for the suggestions. I'll be looking into them.

A thought I had was that since the R-11As had a wear grade of 200, even if I go to a tire with a grade of 300, I would only expect to get another 50% longer life out of them - or probably a max of 15,000 miles.

And then I had another thought (this is getting dangerous!!). Why is it that our rear tires have such a short life? Discussing the situation back in the '70s, the thought then was that all the weight and power went through them. Well now we have front engine, front wheel drive cars. The tires not only hold a weight that is likely heavier, but also transmits all the power AND steering inputs. I haven't seen any reviews from people who describe their driving as "spirited" who get the low mileage we get.
Title: Re: Another tire discussion
Post by: EuropaTC on Friday,March 02, 2018, 09:35:27 AM
1 – Does anyone know what brand and model tires came from the factory on the TCS with alloy rims, 175/70-13 up front and 185/70-13 rear?

The original tyres were/are quoted in the manual, Dunlop SP sports for steel wheels and something called  "Firestone Cavalino wide oval" on the alloys. 

I remember Graham Arnold giving a talk once at a Club Lotus weekend and tyres came up. He was pretty forthright in his views, he basically said that tyres for the road cars were a marketing thing, Chapman was only interested in the best deal he could get and that's why almost all the makers of the day had a recommended tyre on their lists. Personally I used to go for SP Sports when I had 13" wheels, they were very popular over here back then.
Title: Re: Another tire discussion
Post by: EuropaTC on Friday,March 02, 2018, 09:39:17 AM
The difference in tyre grading is interesting BDA but as most manufacturers sell both in the USA and Europe, you'd think we could have a common system, wouldn't you ?   

I like your ratings for G-force, assuming that relates to cornering G-forces it's a pity that it stops at 0.54 and puts everything in the same category after that. Some enterprising soul should come up with AAA for 0.9G and above !
Title: Re: Another tire discussion
Post by: BDA on Friday,March 02, 2018, 10:33:18 AM
Keep in mind that the test for the traction grade is done on wet asphalt and wet concrete.
Title: Re: Another tire discussion
Post by: dakazman on Friday,March 02, 2018, 04:03:47 PM
I normally don't say anything about manufacturers of tires but Dunlop is a definite no for me . A brand new first time urun at 75 mph resulted in a blowout wire brushing the paint off the rear end of my vette?
I do need a complete set of tires , my rims measure 175mm front a n 198 rear ,and thinking of going with 185 front and 215 all 13 inch rims.
Dakazman
Title: Re: Another tire discussion
Post by: EuropaTC on Friday,March 02, 2018, 11:25:35 PM
Keep in mind that the test for the traction grade is done on wet asphalt and wet concrete.

Ahh, thanks for posting that, I didn't realise. Although now you mention it I'm having a "doh" moment because I should have realised the numbers are low when you compare with road tests that mention g-force cornering.

I'm still impressed with the idea though, in fact more so now I know it's a wet test.  Our EU regs on wet performance are taken from a combination of braking and skidding tests, the braking from 50mph, the skidding or wet friction at 40mph. From those results they work out the bar chart comparisons although I've no idea if one test is weighted more than the other.  The rule of thumb is that each bar denotes 1 metre less in stopping distance, so as you move from A->G  you increase distance to stop, so you want as close to A as you can get.

The fuel efficiency is rolling resistance/fuel economy which is of interest to a fleet buyer, but not me. Perversely I look for something at the lower end in the hope that a higher resistance equates to more grip !
Title: Re: Another tire discussion
Post by: BDA on Saturday,March 03, 2018, 05:35:30 AM
It seems that the EU system is a bit more complete. For example, I'm considering Yokohama S.Drive tires. The traction grade is higher than the RE-11As and they have a higher wear grade. Those seem like they're contradictory so I guess the tread of the Yokes is what's responsible for that traction grade (which brings up the question of how much water is used in the traction test. I don't know.) but I wonder how much this is telling me about dry traction. It would be nice to also have a dry traction grade.
Title: Re: Another tire discussion
Post by: BDA on Saturday,March 03, 2018, 05:47:32 AM
dakazman, at least one of the Dunlop models I looked at had bad reviews so they are pretty much off my list.

I guess you're bound by the wheels you have. 185/215 is a pretty big stagger. I don't remember much of the conversation but I was talking to Richard about tires and I got the feeling he thought my 205s on the rear for my engine was larger than he would have used. I'm not dissatisfied with my tire size though.
Title: Re: Another tire discussion
Post by: Certified Lotus on Saturday,March 03, 2018, 05:59:08 AM
I replaced my tires on my 64 Elan with these Yokohama’s. After months of research and then months of trying to find the right size tires in the US for street use I finally secumbed to ordering from the UK and paying a fortune for air ship. Never the less, I am very happy with the overall performance  (read stickiness) of these tires (and this is from a guy who is used to racing slicks and go karts).

A brief video of my Elan S1 driving on a country road on these tires:

https://youtu.be/dgrl1NBuaWc
Title: Re: Another tire discussion
Post by: BDA on Saturday,March 03, 2018, 06:53:03 AM
Nice video, Certified! Those look like nice tires but I don't think I want to pay that much for shipping. I don't understand why certain tire models are only available in certain markets, though. It makes no sense to me.
Title: Re: Another tire discussion
Post by: Grumblebuns on Saturday,March 03, 2018, 07:27:43 AM
Brian,

Unfortunately, the Toyo Proxes T1R are no longer available in 205/50-15 (at least they weren't listed on the retailers I checked and didn't see them on the Toyo website!).

Clifton,

Thanks for the suggestions. I'll be looking into them.

A thought I had was that since the R-11As had a wear grade of 200, even if I go to a tire with a grade of 300, I would only expect to get another 50% longer life out of them - or probably a max of 15,000 miles.

And then I had another thought (this is getting dangerous!!). Why is it that our rear tires have such a short life? Discussing the situation back in the '70s, the thought then was that all the weight and power went through them. Well now we have front engine, front wheel drive cars. The tires not only hold a weight that is likely heavier, but also transmits all the power AND steering inputs. I haven't seen any reviews from people who describe their driving as "spirited" who get the low mileage we get.

BDA, have you looked into the Toyo R1Rs. I believe they are one of those DOT legal track tires but if you are looking for traction as a priority like I am they may be another option.

Your question on short rear tire life on our cars made me wonder how other mid-engine cars of the era fared on rear tire life. I remembered when I was driving my TCS almost every day commuting to work back in the 80s that I was replacing my rears 2 to 1 vs the fronts. On the last two rears I was using, the long lamented Phoenix Stahlflex 3011s, I was only getting between 3000-4000 miles on them. At least for my part, it may have been driving technique. I never resolved the oil starvation issue on long hard right hand corners with the twink engine so I had to back off mid corner when I started to lose oil pressure finally able to get back hard on the gas when the turn started to straighten out wearing out the rears.

Curiously on my 05 Elise, I'm currently on my third set of rears while running the original front OEM tires. I don't have to worry about oil starvation with the Toyota motor so I'm able to keep the power on for a long time throughout the corner and I'm still using up the rears more than the fronts. 
Title: Re: Another tire discussion
Post by: BDA on Saturday,March 03, 2018, 09:29:09 AM
3000 - 4000 miles on rear tires! Yikes!

Those R1Rs have the same wear grade as my RE-11As but better traction. The S.Drives have 50% higher wear grade with the same traction grade (both are better than the RE-11As in traction). Of course those numbers mean a lot less when you actually mount those tries and drive on them. I think I'm going to see if I can get better wear and reasonable grip. If I were tracking or autocrossing, the R1Rs would probably be better.

I think somewhere here I mentioned that when the car was new, the fronts seemed to last forever. Alas, I didn't have a lot of total miles on the two I had (the one I have now is the second one I had) but 50,000 miles seemed possible. We'll see what the final numbers will be but the fronts I have now seem to be following that pattern which is to say the fronts seem to last more than twice - maybe more than three times as long - so I'm a little surprised at your 2-1 ratio.

Out of curiosity, how many miles to you get out of your Elise rears?

Title: Re: Another tire discussion
Post by: Grumblebuns on Sunday,March 04, 2018, 04:46:27 AM
For the Elise rears, I'm estimating around 5000 miles before replacement. The fronts will need to changed out next tire change due just to age, they'll be around 13 years old this year if I got the arithmetic right. The sidewalls still look good.
Title: Re: Another tire discussion
Post by: BDA on Sunday,March 04, 2018, 05:47:05 AM
Yikes! That's not much! On the other hand if you don't put many miles on the car, it forces you to change them before they get too old!
Title: Re: Another tire discussion
Post by: surfguitar58 on Sunday,March 04, 2018, 06:30:21 AM
Folks on one of the BMW forums seem to like Federal SS595 tires, and they are available in both 185/60R13 and 205/60R13, which cannot be said of Toyos except for R888 and R888R models. Suspiciously, the Federal tires are 1/3 the price of the Toyos. (~$50 ea vs $150 ea!) I have seen Federal ss595s mounted on a Europa. Has anyone had experience with these?
Tom
Title: Re: Another tire discussion
Post by: jbcollier on Sunday,March 04, 2018, 07:14:55 AM
The key thing for a Europa tire is that it is true and round.  Any out-of-round or true (side-to-side) will result in vibration issues.

Tires I have experience with:

Vredestein: very good quality, no issues with out-of-round, long-lasting street tire, better than anything back in the day

Michelin "classic" tires from Longstone and others: absolute crap, massively out-of-round and true

Michelin 175/70-13 modern mini-van tires: mostly good quality, long-lasting street tire, better than anything back in the day.  Ask to see each tire spinning.  I went through 6 to find three perfect ones.  Still looking for the fourth.  "Bad" ones are nowhere near as bad as the Longstone offerings.  I'm building a tire shaver so I can lightly shave my own -- only good for fixing out-of-round.
Title: Re: Another tire discussion
Post by: GavinT on Sunday,March 04, 2018, 04:39:26 PM
The key thing for a Europa tire is that it is true and round.  Any out-of-round or true (side-to-side) will result in vibration issues.

Ain’t that the truth.

Way back in the late 70’s I bought a set of Minilite wheels (genuine magnesium ones) that came with some Avon 165/60 tyres. 60 series tyres was considered quite radical for the day.
They were absolutely fantastic and I was revelling in the new found grip.

After a couple of months I detected a vibration and I chased that vibration all over the place. I thought I’d checked everything and had swapped the wheels around a couple of times.

Yep . . it turned out to be the tyres . . all four of them.
I was sorely disappointed because otherwise, they were uncannily good.

Looking back, I wondered if they could have been skimmed much like the Formula Ford guys do but maybe that wouldn’t have helped an out of round carcass. Dunno.
The interesting part of all this was that the out of roundness seems to have developed from nothing. They were great when first fitted.

Anyway, it’s probably still a good idea to see what the Formula Ford guys are running.
They usually know their stuff and are forced to use tyres on relatively narrow rims like a Europa.
In Oz, they’ve recently changed the mandated tyre to the Yokohama A048 . . not exactly cheap though.

https://formulaford.org.au/Portals/0/FFA%20Tyre%20Flyer%20Low.pdf