Tires (Hijacked from Barn Find)

[kayemoxon]

Hi
I'm enjoying your story - Regarding tyres (that's the way we spell it here in the UK). I would agree that tyre manufacturing has come a long way in the last 20 years and most of the imported far eastern tyres are exceptionall good for the price.

I would advise caution in the choice of tyre size. My car (250sl 1967) should have 185/HR14 tyres. This translates directly to 185/80xR14. Your choice of 195/75x14 is popular (in fact my car had this size on 4 years ago when I bought it). However, the difference in profile of 75 to 80 makes a noticeable difference in the gearing making your speedo read an error of about 7mph

I am currently having a new set of Hancook K715 Optimo  185/80xR14 tyres fitted at £60 each balanced and fitted. I have read excellent reviews on this tyre. Also my speedo will read spot on in future and the car should be more relaxed at speed as my rpms will drop a little due to the slightly larger circumference of the tyre.. Check it out if it is available in USA

Regards-  keep up the great writing - and best of luck with the brake calipers - you may need it!
Kaye

[mdsalemi]

FWIW:

I despise Hankook tires.  In decades of driving, I've never had but two flats.  Both on Hankook tires on my last car, a Ford Flex.  Ford chose them, I'm sure for one reason only: price point.  Then the tread separated on one of the front tires.  The Ford garage replaced both front tires due to excessive wear at about 15,000 miles.  That's not very long life.  The same model ranges of the car in higher trim/cost levels are fitted with Michelin or Pirelli.  The ones I had were, all weather, all season, jack of all trades (master of none) tires.

The "Optimo" name is one applied to many Hankook tires, and your experience might very well be different.  If I was buying tires, I would not choose Hankooks, but that's just based on my experience.

As long as you stay with blackwall tires, there certainly are better tires out there, albeit at a higher cost.  Many are speaking highly of the Vredestein Sport Classic on this forum.

[114015]

I fully agree with what Michael says.

Vredestein Sprint Classic should be the choice. 185/80R14 90H

You "could" also go with the Michelin tyres (tires) but those are extremely expensive.

Just my 2 cents....

Achim

[kayemoxon]

Yes Achim,
I agree the Vredestein Sprint Classic is a nice tyre and probably the top choice available at an affordable price for these cars.
However, we are able to make our own decisions on what we fit to our cars based on the best value for money and available evidence.
Contrary to an earlier opinion, we here have very positive reports on the current Hankook tyre products being sold in Europe. Check this link

http://www.tyretest.com/pkw_sommerreifen/hankook/optimo_k715/index.html

The point of my earlier post was to draw attention to the fact that correct tyre size AND profile is important. Not only do many owners fit 195/75x14 -several members on this forum are using 205/70x14! Good luck to them - they are entitled to fit whatever they choose. Its more rubber on the road and it looks 'meaner' I suppose. The car will sit lower and maybe some like that.

The point I'm making is : you are messing with the gearing/speedometer calibration of your car
The lower profiles will result in higher revs at cruising speeds compared to the standard fitment!

'You pay your money and you take your choice'

Here in UK our legal cruising speed is 70mph and I do this comfortably now on my Hankooks (which I had fitted yesterday) I know its early days and I will keep you informed if I have to eat my words.
Incidentally, I have the top down today for the first time this year.  The weather today in UK is beautiful. Not a cloud in the sky and quite warm. A lovely drive to the office.
Regards to all,
Kaye

[Naj ✝︎]

________________________________________________________________________

I would advise caution in the choice of tyre size. My car (250sl 1967) should have 185/HR14 tyres. This translates directly to 185/80xR14. Your choice of 195/75x14 is popular (in fact my car had this size on 4 years ago when I bought it). However, the difference in profile of 75 to 80 makes a noticeable difference in the gearing making your speedo read an error of about 7mph

________________________________________________________________________________________


The point of my earlier post was to draw attention to the fact that correct tyre size AND profile is important. Not only do many owners fit 195/75x14 -several members on this forum are using 205/70x14! Good luck to them - they are entitled to fit whatever they choose. Its more rubber on the road and it looks 'meaner' I suppose. The car will sit lower and maybe some like that.

The point I'm making is : you are messing with the gearing/speedometer calibration of your car
The lower profiles will result in higher revs at cruising speeds compared to the standard fitment!

Regards to all,
Kaye

Hi, Kaye,

I have to disagree (a bit !) about the changing of gearing using alternative tyres.

By using 195/75 x14 instead of 185/80 14 tyres, your speedo would be off by 0.5%
Using 205/70 x14, it would  be off by 1.4%

In both instances, the speedo would be reading higher than the actual.

[I  used this site to calculate the differences:

http://www.miata.net/garage/tirecalc.html  ]

Calibration of the speedo could be off by a much larger %. This is quite easy to check these days with the speed calculated by satnav.

Like you say, its just a matter of personal choice, but I suggest gearing is not too much of an issue

Yes, very nice day today here to. I should be out driving!!
Enjoy the drive back

Naj

[snowyt 69]

Okay wait a second:

I simply mentioned the tire type and size I intend to put on Snow White in response to an inquiry on my thread. I did not intend this to become a discussion on tire types/sizes, speedometer errors or what not.
This thread is not about any of these things. It is about love of a neglected car. Last I looked, I didn’t even have brakes. What do I care about potential speedometer error? Besides, the speed limit down here is quite simple. It is as fast as everyone else is going. Sometimes they go fast. Sometimes they go zero. This is the speed limit, and your speedometer is irrelevant.
If you want to talk the pros and cons of Hankook tires, by all means do it. Somewhere else.
If you want to talk of why you love your car, I am all ears.

[kayemoxon]

Sorry we took the limelight off you for a moment!
I'm sure that if the tire/tyre issue had carried on it would have been moved to the'Drive train...' section

[mdsalemi]

This forum, like many others does this on occasion.

One topic engenders another and that's what learning is all about.  Some people make choices without complete information.  To me, and many others, an accurate speedometer is important.  So are discussions of various tire options, and sometimes these things fall out of other discussions.

This is far from the first thread to change a direction and it won't be the last.

[Peter van Es]

But I (as the admin) can split threads... so now this is in it's own thread, in the right section...

Peter

[gugel]

Not only do many owners fit 195/75x14 -several members on this forum are using 205/70x14! Good luck to them - they are entitled to fit whatever they choose. Its more rubber on the road and it looks 'meaner' I suppose. The car will sit lower and maybe some like that.

3/16" lower, is all.  Not something most people could detect with the naked eye

[snowyt 69]

Tires, Speedometer Errors and other thoughts:
The funniest thing about all of this is that I researched potential tire choice, type, and size on this forum already. I felt confident that given the marginal discrepancy in speedometer reading, the ease of procurement, that a decent 195/75/R14 was the way to go. This information is what biased my choice in the first place.
Michael, you of the gorgeous red ’69 280 SL. Regarding speedometer accuracy, it used to be a factor in the road tests done by Road and Track magazine when your car was first built. It was part of their road test data sheet. I read Road and Track and Car and Driver like bibles when I was a kid, as I loved cars. As I remember, speedometer error tended to range from the optimistic, to the wildly optimistic. A ten per cent variance at an indicated 100-MPH was not uncommon. Meaning the car was actually travelling at 90-MPH when it indicated 100-MPH. These were factory original discrepancies, only altered by radar accuracy. I do not know the discrepancy of the 280 SL, but I'm sure you could research it.  The Germans were pretty good at these things, but it was terribly rare that anyone got anything right. You might find such a search an interesting read. It might also allow to you blast further into your speedometer reading without fear of retribution.
I am not pissed at anyone for wanting to talk about tires. I do not want to stem the flow of information, and I am aware how information changes forms.
But Barn Find is for anyone who dreams of taking a shot at the improbable.
Tires are just round rubber donuts that get the job done.

[badali]

I have 205 75 14 on my 230 SL.  When driving with my GPS it shows my speed to be about within 1 MPH of the speedometer at 60 -70 MPH.  My 280 SE 4.5 has 195 75 14 and the speedometer indicates 60 mph but is actually going about 57 MPH.   It seems to be what I read in the original road test from road and track.  You can use your GPS to determine your speed with each size tire.

[graphic66]

My 230SL with 205/70/14's has almost perfect accuracy from the speedometer also, according to my GPS. I have the speedometer and rear axle from a 250Sl installed.
   Almost all newer cars read faster than they are going. I keep wondering when the public will wise up and see that the auto makers are stealling millions of warranty miles a year from them. Think about it, you get a 60,000 mile warranty with a fast reading speedometer. You reach the 60,000 mile mark at about 57,000 miles if the speedo is reading 3 MPH fast by my quick math. If you are selling millions of cars the saving/theft is huge, warranty miles cost money, and you pay for them when you purchase a car. Sorry for the hijack, but this subject makes me angry.

[mdsalemi]

I keep wondering when the public will wise up and see that the auto makers are stealling millions of warranty miles a year from them. Think about it, you get a 60,000 mile warranty with a fast reading speedometer. You reach the 60,000 mile mark at about 57,000 miles if the speedo is reading 3 MPH fast by my quick math. If you are selling millions of cars the saving/theft is huge, warranty miles cost money, and you pay for them when you purchase a car. Sorry for the hijack, but this subject makes me angry.

I'm no attorney but this sounds like a great basis for one of those large class-action lawsuits, yes?

[knockmacool]

I'm no attorney but this sounds like a great basis for one of those large class-action lawsuits, yes?

Assuming the odometer and speedometer are the same instrument... Are they?

[badali]

In the old road and track articles the speedometer error was not consistent with the odometer error.  They may have 2 separate functions/instruments but I'm not sure.  Sometimes the odometer breaks but not the speedometer or vice verse.

[Tom Colitt]

Well, the odometer feeds off the speedometer, but it can still have a substantial inaccuracy of its own as parts wear out...

[knockmacool]

My point is the odometer can be clocking correctly and the speed indicated is just a matter of where you want to draw 60MPH on the dial...Overstating the speed doesn't necessarily overstate the mileage.  I guess I don't buy the conspiracy.