Tyres for elan

[bcmc33]

I shalll keep a steel wheel as the spare.

I'm still bemused by the notion that wider wheels have to move more water in the wet. I hope someone can explain that to me.

I did my very best to try to fit 6" wheels as I had a really good offer from Minilite but failed due to fouling on the rear strut despite small springs.

I've yet to get tyres for my 14x5.5 Minilites but have sort of decided to use 175/65 - have to make a decision in the next couple of weeks.

[paddy]

I'm still bemused by the notion that wider wheels have to move more water in the wet. I hope someone can explain that to me.

It seems logical to me. The volume of water displaced for every unit of distance travelled is (simplistically) the depth of the water times the width of the tyre. I understand the logic that says that the contact patch area is no different (just a wider shape in the case of a wider tyre), but it's only the width of that patch that determines the amount of water that needs to be displaced.

Paddy

[elanakscl]

I was thinking that if I replace the tyres I have I would go for 175/70. I have room to do this. I don't want to go to a lower profile; the look is out of keeping with the car IMO, and (having a 3.9 diff) I would be making the gearing situation worse.

Michelin XAS FF - good grip, expensive, sticky (grit problem) - I've not found them in 175/70 - Bruce says they're too big to fit in the spare wheel well (what size was that?)
Uniroyal R680 - cheap, recommended by Paul Matty - 175/70 available
Avon CR6ZZ - no comments - I've not found them in 175/70
Yokohama (A032R?) - Rohan's choice - I've not found them in 175/70
Vredestein Sprint - a couple of people say they're very happy with them - I've not found them in 175/70
Toyo RA/R888 - no particular feedback on them
Any comments? Suggestions for local suppliers?
Paddy[/quote]

In North America www.tirerack.com lists Sumitomo htr200 in a 175/70-13 size, 41 USD, as a high performance summer tire. Are you sure 175 width tires clear S1 fenders? I'm using 165/65 Bridgestone RE92's all seasons on my lowered S1 now, but would like 175's.

[paddy]

Are you sure 175 width tires clear S1 fenders? I'm using 165/65 Bridgestone RE92's all seasons on my lowered S1 now, but would like 175's.

In my case yes, because I have 26R arches. With the stock arches I think it's unlikely.

Paddy

[neilsjuke]

http://www.carbibles.com/tyre_bible.html

I have Uniroyal R680 on the Sprint seem good all round on the road
Neil

[prezoom]

I currently have the Sumitomo 175/70-13 tires on my S2. I was looking for the maximum tire diameter I could fit to offset the lower 3.9 diff, way too many revs on the freeways. The car has mild flairs done by the PO. I figured with the low cost of the Sumitomo's if they didn't work or I didn't like the way the car drove, the loss would be minimal if I decided to change to a different tire. So far, I have not had the car go loose or understeer in spirited driving. Some day I'll get it to a large paved area and play with a skid pad type of test until the car breaks loose. With the car ride height set at the lowest possible position, during bump there is some slight tire rub. Yesterday I raised the car approximately 1 inch in the rear and a 1/2 inch in the front for a 1300 mile tour I will be taking in a week. The reason for raising the car is I will be taking a passenger, as his Alfa is not ready, and his additional luggage. The past two tours have been by myself, with minor contact only when pushing a little hard and encountering dips and bumps. Normally I can live with a little "zip" once and a while. The lowered ride height does have some problems with the the exhaust pipe hitting over some rough areas......but I like the "look".

Rob
26-4889

[paddy]

Interesting. Is that the HTR200 ?

http://www.tirerack.com/tires/tires.jsp ... el=HTR+200

Paddy

[msd1107]

If you are looking for the largest diameter tires to decrease the revs on the freeway, here are some candidates:

175/70-13 is 917 rev/mile, 22.6 in diameter.
185/70-13 is 893 rev/mile, 23.2 in diameter. (I have used these in the past)
185/60-13 is 956 rev/mile, 21.7 in diameter. (Much too small)
155-13 is 912 rev/mile, 22.8 in diameter. (Slightly larger than 175/70-13)
165-13 is 887 rev/mile, 23.4 in diameter. (This is the easiest and best. If you can stand the cost of Michelin XAS tires, you get good cornering. With the 23 tooth transmission gear for 3.55 diff, you need a S4 speedometer for proper odometer reading. If you have an early speedometer with 1000 turns/mile, send it to Nisonger or other speedometer specialists to get changed to 960 rev/mile, a 20-48 tooth combination in the odometer. The S4 speedometer is 980 turns/mile, suitable for 155-13 tires, close but 960 is closer for 165-13 tires.)

If you go to 14 in Minilites,
185/65-14 is 884 rev/mile, 23.5 in diameter.
185/60-14 is 915 rev/mile, 22.7 in diameter.

(For those of us with nothing better to do, in a few days I will post an updated spreadsheet that allows someone to determine the best transmission/speedometer gear pair, or the best Smiths odometer gear pair for proper odometer calibration for any wheel/tire, transmission gear pair, speedometer turns/mile or differential ratio)

David
1968 36/7988

[prezoom]

Paddy,

Yes, they are the HTR200's. As soon as I figure out how to post a picture, I'll give you an idea of the size of the flairs. Or I can send the picture to Gary and he can add it to his "flair" file. David has seen the car.

Rob
26-4889

[prezoom]

Actual rolling circumference for the Sumitomo HTR 200 175/70-13 is 70.5 inches according to my stagger tape. Measured down the middle of the tire with 25psi. This is with 5000 miles on the tire.

Rob
26-4889

[msd1107]

Rob,

Interesting. 70.5 in is .9% different from the diameter represented by 917 rev/mile.

Incidentally, the tech specs for the Sumitomo 175/70-13 tire are a diameter of 22.7 in, or 71.3 in circumference.

The 917 rev/mile figure is the average of different tire manufacturers reported tire rev/mile figures, which ranged from 909 rev/mile (71.8 in circumference) to 928 rev/mile (70.3 in circumference)

To get lower revs on the freeway, going to 3.77 or 3.55 diff is effective. For years, I ran a CR trans with 3.55 diff and 165-13 and then 185/70-13 tires.

Of course, when you get your bell housing completed, then you can bring in a T9 and really bring down the revs.

David
1968 36/7988

[fjbm]

Hi

I'm planning on keeping the standard size of the tires used on my S4 and I'm going to use Bridgetone's B 330 EVO 155/80 R13 79T CZ.

Does anyone have experience with this?

Is it really necessary to go over 155/80 on a road car? Even if we want do do some showoff once a month?

Thanks

[peterako]

The chassis and suspension on the Loti are so good that I am more than happy with my standard 165/70's on my +2!

Handling and roadholding is more than adequate to keep up or out pace most things on the road

Peter

[garyeanderson]

Rob sent a couple of pictures with the Sumitomo HTR 200 175/70-13
the arches look very nice and the tires fill all of the available space.


p.s. - rob, check the left rear for a missing peg...

[elanakscl]

Yes, they are the HTR200's. As soon as I figure out how to post a picture, I'll give you an idea of the size of the flairs. Or I can send the picture to Gary and he can add it to his "flair" file. David has seen the car.

Rob
26-4889[/quote]


Nice look with the subtle flares.
Seems the 175/70's will be too big for stock fenders. The pix are very helpful.