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Tue Oct 25, 2011 11:13 am

I just ordered vredestein 155sr15 for my 73 super beetle - they look really narrow, but a bunch of posts on here (plus glove box sticker) seem to indicate this is the right tire for stock.

Can someone confirm this is the right tire, I hate to have to ship em back and pay that money...

Tue Oct 25, 2011 11:23 am

the Og size was 155 or 165 sr 15 so thats correct.

Tue Oct 25, 2011 1:17 pm

yes 155-15 are correct

Tue Oct 25, 2011 1:24 pm

Actually, it was mid 1972 that VW changed to the 6.00 x 15 for the stock bias plies and went to the 4.5" wheels. And that size is more like 165 than 155 in metric.

Tue Oct 25, 2011 2:42 pm

Yes it appears my wheel width is 4.5". Still the sticker in the glove box does say 155sr15 for radials and visually looks like it will work. The difference in width on a 165mm vs 155mm is only 0.39"...which does seem that major being as it will be split on each side of the wheel.

My gut tells me itll work, but is anybody running them?

Tue Oct 25, 2011 2:56 pm

They'll work. They are also smaller in diameter than 165s so the speedometer and odometer may read faster (more miles) than actual.

Tue Oct 25, 2011 11:54 pm

glutamodo wrote: Actually, it was mid 1972 that VW changed to the 6.00 x 15 for the stock bias plies and went to the 4.5" wheels. And that size is more like 165 than 155 in metric.
I agree. A 155 is the wrong tire for a 73 Super. The biggest effect is the hit on your gearing. Your freeway rpms will be significantly higher with the smaller tire. You need 165s.

Wed Oct 26, 2011 9:55 am

I see how the gearing would change, but is it that big of a problem? I guess what I am thinking is that the earlier 4" wide rims ran 155's and that would have had the 155 diameter - there wasnt a change in transmission that i am aware of, so how would diameter really negatively impact transmission?

Wed Oct 26, 2011 10:29 am

Personally, I wouldn't think so. I don't know a whole lot about the gearing but if it says 155 in the glove box, then why not?

Wed Oct 26, 2011 12:27 pm

One thing to remember is when these tire sizes changed, it wasn't 155 and 165s that VW were putting on the cars, it was bias ply 5.60 and 6.00 x 15. Bias ply tires are usually larger in diameter than radials. If you look at the published specs for the various tires that places like Coker Tire sell, you'll note that those two bias ply sizes are like 25.8 and 26 inches tall. Compare that to 24.8 and 25.4 for the 155 and 165 tires.
There was in fact, a transmission change. Not immediately but they did make a change. The tire change did happen in middle of model year 1972. The transmission didn't change until 1973. That's when they went from the 4.125 to the 3.875 differential on the Bugs. BUT, they also changed the 4th gear, so the effective ratio really wasn't that much different than before.

The difference between (24.8 and 25,4" tires) 155SR15 and 165/80R15 tires, with a 1973 transmission, is noticable but not terribly so. At 70MPH it will make it so your engine runs about 80 RPMs faster.

-Andy

Wed Oct 26, 2011 12:54 pm

Andy, this is good info. I like it when there is data to go on. I called Coker and they told me I could run the 155's, so based on all the data, I think I am going to run them and see how it goes. I only bought a pair, so I may actually stick the 155's on the front end - it will affect the speedometer obviously, but it won't cause me turn higher RPM's that way. When I buy my next pair, I will probably go back to 165's and stick em on the rear.

Thanks for all the input from everyone...good discussion in my opinion...exactly what the forum should be used for.

Wed Oct 26, 2011 1:23 pm

Yes, you can run them. For a while a few years ago, Coker was selling a 175/80R15 tire. That's wider and taller, of course. I thought about trying those on my 62... where I have a big-bore 40HP, and increasing the diameter like though would be an "easy" way to gear the tranmission a little bit "taller" for the larger engine than stock. But then Coker ran out and never got that size back. (someone posted a photo of their bug, a late convertible if I remember, with those tires on it, and it looked pretty decent to me, but I can't find the post now)

Speaking of stock tires in the 70s more, the type 4 was the only model you could get with factory radials. I think the sedans had 155s and wagons 165s. So 165R15 was an available size back then. But I think 155s were more common, at least at first, but 165s soon became the standard replacement tire size during the 80s. But in the 70s, they were optional on bugs. I think one option or maybe on one of the special edition models, was actually a 175/70R15, I've seen it listed on one of the various tire pressure decals before. That tire would have been smaller than any of the ones we've been talking about.

I've read that the ratio on R and SR series tires back then was more like 82 instead of the 80 you see today. So they may have been a little bit taller as well.

I think you'll be OK with the 155s but I'd do like you said, and plan on 165s next time 'round.

-Andy

Tue Nov 01, 2011 3:47 pm

It appears i have a 4" rim for the spare. Will one of old 165/80r15's fit on a 4" rim as a spare?

Tue Nov 01, 2011 4:12 pm

I like the look of the 165/80x15 over the narrower 155 BUT a 165 on a 4.5" rim is a very tight fit when its aired up properly (especially with the air canister for the windshield washer). BTW, The '70-76 VW-Porsche 914 used 155/80x15 on the low end (non-appearance group originally) on 4.5" rims and 165/80x15 on the wider 5.5" steel and alloy rims.

Tue Nov 01, 2011 5:30 pm

b15605 wrote: It appears i have a 4" rim for the spare. Will one of old 165/80r15's fit on a 4" rim as a spare?

Yes, it will fit and work fine. So you have a 165/80R15 currently then? You really didn't see that size until a few years ago, it was almost always 165SR15 that you saw before that. Those Porsche 914s mentioned above, they didn't come new with tires marked with an 80 profile, they used 155SR15, 165SR15 and 165HR15, which may not have been precisely 80% ratio, (but close)

But you should not have any problems in sticking your best current tire on that 4" spare rim.