Minilite wheels

[Old English White]

I prefer the look of the minilites / panasport but if they are heavy what to do? the 26R wheels seem hard to get in knock on too?

Not hard to get , only expensive ...
Christian.

[bcmc33]

FWIW, my 14x5.5 Minilites with 175/65 tyres weigh 30lbs.

[msd1107]

Brian,

Did you get a chance to weigh the tires and wheels alone?

30 lbs for the tire/wheel combo is not too bad. The stock steel wheel is pretty light at 12+ lbs. So it would only take a 17 lb tire to get close to 30 lbs, and many 165-13 tires approach that.

David
1968 36/7988

[bcmc33]

Did you get a chance to weigh the tires and wheels alone?

A wheel alone weighs 7kg (<15lbs) on my simple scales.

[freddy22112211]

<<The standard high profile tyres on the 13" wheels, in my opinion, don't look good. You could fit lower profile tyres, say 70's, but the rolling radius will cause concerns with the speedo.>>

Brian,
The 165/70s rolling radius is not that much different to the 155/80s.
Gordon

[bcmc33]

The 165/70s rolling radius is not that much different to the 155/80s.
Gordon

165/70 tyres on 13" wheels will result in a speedo error of 4mph. i.e. at 70mph the speedo will read 66mph.
165/70 tyres on 14" wheels will result in a 1mph error as will 175/65 tyres.

I fitted 175/65 tyres on 14" Minilites as, IMHO, they looked they looked good on a friend's Elan, and drive much better than the standard profile.

[msd1107]

155/80-13 tire is 912 rev/mile
165/80-13 tire is 887 rev/mile - a 2.82% difference from 155-13 (I upgraded from 155-13 w 5.5 wheels at first chance)
165/70-13 tire is 942 rev/mile - 3.29% fast over 155-13
175/70-13 tire is 917 rev/mile - 0.57% fast over 155-13
185/70-13 tire is 893 rev/mile - 2.07% slow over 155-13, 0.69% fast over 165-13 (I ran this for years)
185/60-13 tire is 956 rev/mile - 4.77% fast over 155-13, 7.72% fast over 165-13
165/70-14 tire is 899 rev/mile - 1.37% slow over 155-13, 1.41% fast over 165-13
165/65-14 tire is 925 rev/mile - 1.48% fast over 155-13, 4.34% fast over 165-13
175/70-14 tire is 880 rev/mile - 3.51% slow over 155-13, 0.79% slow over 165-13
175/65-14 tire is 905 rev/mile - 0.76% slow over 155-13, 2.04% fast over 165-13
185/60-14 tire is 915 rev/mile - 0.29% slow over 155-13, 3.12% slow over 165-13 (This is what Spyder does)
185/65-14 tire is 884 rev/mile - 3.12% slow over 155-13, 0.39% slow over 165-13

So if you are replacing 155-13 tires, try to get close to 912, if replacing 165-13 get close to 887.

There is a downloadable spreadsheet at elan-f15/updated-spreadsheets-t18445.html that lets you see all this and to get the best transmission drive gear or speedometer gear combination.

David
1968 36/7988

[mac5777]

Hi David, I just replaced my tires with 155x80x13s that had a diameter of 22.8 inches. Other brands of the same size measured smaller diameters. My speedo and tach may not be correct but at 65 mph the revs now show 3300 RPMs, which was lower than before. How close are the revs at 65 using your calculations? Sorry to say I still fumble around with your spreadsheet. I'll try the latest one again.
I have a 3.55 diff and a semi close trans.
Thanks again for all of your technical knowledge,

Sarto

[freddy22112211]

My personal view is that the speedo accuracy is of no importance, but other considerations are (perhaps something to do with the fact that my speedo wasn't accurate anyway!). Of critical importance would seem to be: 1. do the tyres fit! 2. steering too heavy? 3. looks - very wide tyres look wrong on an elan.
Gordon

[bcmc33]

Of critical importance would seem to be: 1. do the tyres fit! 2. steering to heavy? 3. looks - very wide tyres look wrong on an elan.
Gordon

From my point of view the tyres fit perfectly, steering weight cannot change if you use the same pressure, and the lower profiles look so much better than the standard 83's.

[msd1107]

Sarto,

22.8 is as close as you can measure. 65mph is close to 3,500 rpm. Try to take a portable GPS with you that reads the mph. That will get away from the speedometer error if it exists. I can bring my portable GPS with me the next time I come up.


Gordon,

It is too bad that your speedometer was not properly calibrated. If you travel with a portable GPS, you can ignore the analog speedometer readings. But sometimes, the bad speedometer readings also indicate odometer inaccuracies. Using the tools available here, you can determine from your tire size and differential ratio what the gearbox speedometer drive gear tooth count should be and compare it with what is in your gearbox. Often, it is not correct. If you cannot get the correct speedometer drive gear, the spreadsheet allows you to get the best gearing in the speedometer itself. A shop that rebuilds Smiths speedometers can install the optimum gear pair for you (which gives accurate odometer readings) and calibrate the speedometer. But many people do as you do and live with crappy data.

What tire looks good is a matter of personal taste. I liked the looks of my car when I went from the 155-13 to 165-13 tires, and also with 185/70-13 tires. But others have their own preferences.

David
1968 36/7988

[freddy22112211]

Brian,
I've often wondered about the cause - but the steering on my car is way heavier with the wide tyres - could it be that the 155s are old, not very sticky, rubber?
Gordon

[mac5777]

Hi David, I want to correct my last post to reflect my speed was at 60 not 65 to get the 3300 rpm reading. The 22.8 diameter was off of the tire manufacturer's specs. The side by side view the new tires towered over the worn 145x80x13 that I replaced. The new 155 tires perform great on Panasports wheels 13x5.
Let me know when you are coming up again.
Thanks again, Sarto

[msd1107]

Sarto,

Yes, 60 would be 3,250, as close to reading 3,300 as you could discern. So you look really good.

Now if everybody else was as close!

22.8" is the nominal diameter for a 155-13 tire. But different manufacturers come up with different final running diameters. Rohan had a tire marked as 185/60-13 that actually came out with dimensions like a 185/50-13.

If there is a measured mile or 10 mile stretch, you could check the odometer accuracy. Or you could check the gearbox speedometer drive gear to see if it is the 23 tooth one. That should be correct for your 155-13 tires, 3.55 differential, and 1000 TPM speedometer. When you went to the 3.55, do you remember if they changed the transmission gear also?

David
1968 36/7988

[bcmc33]

Brian,
I've often wondered about the cause - but the steering on my car is way heavier with the wide tyres - could it be that the 155s are old, not very sticky, rubber?
Gordon

Gordon,

I was never really bothered about slightly heavy steering at very low speeds but did make an attempt when I fitted the 175/65's on 14" wheels to make it a little lighter by increasing the front pressures up to 23psi - this resulted in the car being very skitty at higher speeds. In the end I went back to the standard 18/23 psi fr/rr and the car is very stable.


I'm a little puzzled about the tyre diameter debate. The 175/65 14 tyre has a free state diameter of 577mm (22.72"), and a rolling diameter of 555mm (21.85"). The car has a 3.54:1 diff and green speedo gear, so I was very pleased (and surprised) to find that in 4th gear the speedo was very accurate at 30, 40, 50 & 60 mph in relation to a rolling road speed indicator.