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Sun Oct 24, 2021 5:50 pm

155/80R15 or 165/80R15

Which size is more like original tires for my 1966 bug?

Sun Oct 24, 2021 6:15 pm

Original tires for your '66 were 5.60x15 bias ply tires.

mukluk wrote: A 5.60x15 tire is ~25.8" in diameter, carcass width of ~5.6", and tread width of ~4"; the standard VW optional radial of the time was 155SR15 which is ~24.8" in diameter, carcass width of ~6.1", and a tread width of ~4.25"; while a 165R15 is ~25.4" in diameter, carcass width of ~6.4", and a tread width of ~4.75". As can be seen from those specs, there really isn't a true radial equivalent to a 5.60x15 bias ply tire -- you have your pick of either fairly close in the width department (155SR15), or you can get pretty close in the heighth department (165R15), but you cannot have the same overall dimensions as a 5.60x15. You have to decide whether close to correct heighth or width is more important to you.

Sun Oct 24, 2021 6:50 pm

Thanks! So 165 has the most similar rolling diameter.

Sun Oct 24, 2021 7:36 pm

I suppose it's none of my dang business, but didn't you put new tires on the Beetle less than a year ago? :?

Sun Oct 24, 2021 7:48 pm

iowegian wrote: I suppose it's none of my dang business, but didn't you put new tires on the Beetle less than a year ago? :?

I sure did! Switched the “cement-ride” BFs to softer Nexxen, but always had plans to going back to whitewalls. Got a notification today from a vendor about 155s being available, so I just posted the first question that popped into my head. 🤪
That, plus my 165s don’t fit in the spare tire well, so…

Love this site. It’s like Siri. “Hey Samba” LOL

Sun Oct 24, 2021 8:11 pm

I just put Vredestein 155s on my '66 and I absolutely love them. Nice ride, they stick like glue and look great ---but they are blackwall, so they wouldn't work for you. In my opinion, 155s look more size appropriate than the 165s that I took off.

Mon Oct 25, 2021 10:09 am

FWIW after way too many hours reading threads on this very same debate i went with the 155's. I had 165's for years and IMO they looked too big and as already stated did not fit the spare tire well. Mine also rubbed at full lock. (My car is one family car and never hit so i can confirm no damage.)

To that end though i found a few threads showing that not all 165's are the same physical height. I am sure that is the same for any given tire size across brands. In the end it is what you want and what you think looks right if your going radial.

I went with F560 155R15 black wall's because that was original and man white walls are ALOT of money now days. :)

Mon Oct 25, 2021 11:57 am

As an added bonus, when I switched from 165 to 155 the top speed increased by nearly 4 mph. :lol:

Mon Oct 25, 2021 12:30 pm

iowegian wrote: As an added bonus, when I switched from 165 to 155 the top speed increased by nearly 4 mph. :lol:

Lower wind resistance from the narrower tires, right?
And it will get better the more smooth the tread pattern, so you can look forward to that later.
Don't forget to lower your antenna for the same reason.
;-)

Mon Oct 25, 2021 2:56 pm

Stockholm VW wrote: iowegian wrote: I suppose it's none of my dang business, but didn't you put new tires on the Beetle less than a year ago? :?

I sure did! Switched the “cement-ride” BFs to softer Nexxen, but always had plans to going back to whitewalls. Got a notification today from a vendor about 155s being available, so I just posted the first question that popped into my head. 🤪
That, plus my 165s don’t fit in the spare tire well, so…

Love this site. It’s like Siri. “Hey Samba” LOL

165's don't fit in the spare tire well? My 165 spare fits just fine.

Mon Oct 25, 2021 3:21 pm

rcroane wrote: 165's don't fit in the spare tire well? My 165 spare fits just fine.
Spare tire wells and 165 tires do both vary a bit in size. :wink:

Mon Oct 25, 2021 3:31 pm

mukluk wrote: rcroane wrote: 165's don't fit in the spare tire well? My 165 spare fits just fine.
Spare tire wells and 165 tires do both vary a bit in size. :wink:

Interesting....didn't know that. I'll be buying new tires soon and was going to get 5. I think I'll just keep my existing spare since I know it fits!

Mon Oct 25, 2021 3:40 pm

@rcroane
If you stick with the same brand and style as the old spare, the new one should still fit. Variations in tire width are fairly common from one brand to another and even sometimes from one style to another within the same brand.

My spare well size comment is to point out that besides some little variance in measurements due to manufacturer's tolerances, the effects of decades of use and damage/repairs can quickly result in a specific 165 spare fitting just fine in one car whilst being a "round peg, square hole" issue with another car.

Mon Oct 25, 2021 4:13 pm

mukluk wrote: @rcroane
If you stick with the same brand and style as the old spare, the new one should still fit. Variations in tire width are fairly common from one brand to another and even sometimes from one style to another within the same brand.

My spare well size comment is to point out that besides some little variance in measurements due to manufacturer's tolerances, the effects of decades of use and damage/repairs can quickly result in a specific 165 spare fitting just fine in one car whilst being a "round peg, square hole" issue with another car.

Normally I would, but my tires have a date code of 458, which means they are 20+ years old (in surprisingly good condition with no signs of dry rot). They are Dunlops (spare is Pirelli with 1988 stamped on it) so not sure I can still get those. I had my eye on a set of Vredestein's.

Mon Oct 25, 2021 4:14 pm

mukluk wrote: rcroane wrote: 165's don't fit in the spare tire well? My 165 spare fits just fine.
Spare tire wells and 165 tires do both vary a bit in size. :wink:
I agree. I would also think that 165s mounted on 4” wide stock wheels have a better chance of sliding into the spare tire well than 165s mounted to 5.5” wide wheels? Its not just the tires.

I could not get my 165 on a 4.5” wide stock steel wheel to fit into the spare tire well unless I let the air out. Then it could be forced in. The same wheel with a (nearly bald) 155SR-15 slid in and out easily.

Tue Oct 26, 2021 10:14 am

iowegian wrote: As an added bonus, when I switched from 165 to 155 the top speed increased by nearly 4 mph. :lol:

The speedometer, with 155, become optimistic. Probably this is the speed increasing.

If you look at the back of the speedometer there should be a "0.5" printed.

This 0.5 indicates that the speedometer (and the odometer) are designed to consider a full revolution of the wheel as 2 meters, because 2 meters is exactly the length of the original 5,60/15 bias tire. The same (I suppose) with speedometer set in mph.

With 155/80/15 the length is no more 2 meters, i think about 1,9 meters... so the speedo/odometer reports higher speed and distance than real.

Tue Oct 26, 2021 2:27 pm

rcroane wrote: mukluk wrote: rcroane wrote: 165's don't fit in the spare tire well? My 165 spare fits just fine.
Spare tire wells and 165 tires do both vary a bit in size. :wink:

Interesting....didn't know that. I'll be buying new tires soon and was going to get 5. I think I'll just keep my existing spare since I know it fits!
I have one Metric tire in 165 that is 1/2 taller than the Nexen 165. :(

Wed Oct 27, 2021 2:15 pm

iowegian wrote: As an added bonus, when I switched from 165 to 155 the top speed increased by nearly 4 mph. :lol:

With 165s my speedometer is showing 2-3 mph too slow, so a set of 155s might correct that. 🙂

Did you notice any change in rpms at highway speeds, or is it not noticeable?

Wed Oct 27, 2021 4:00 pm

Stockholm VW wrote: iowegian wrote: As an added bonus, when I switched from 165 to 155 the top speed increased by nearly 4 mph. :lol:

With 165s my speedometer is showing 2-3 mph too slow, so a set of 155s might correct that. 🙂

Did you notice any change in rpms at highway speeds, or is it not noticeable?
I was sort of joking about the speed increase----but not totally joking.
Now the car feels happy at 75 (I know about the speedometer error), where 65ish was its "sweet spot" with the twenty-year-old Nankang 165s. Maybe reduced rolling resistance is a factor with this particular brand of 155s ? But not as dramatic as it was when I switched from bias ply to Michelin X on my then-new 1967 Cougar XR7. :D