Hard to hard to find tall skinny tires... - Fuel Economy, Hypermiling, EcoModding News and Forum

nvygw171 · 11-06-2009, 11:44 PM

Hi all, love this forum. I've been learning a lot here and have already implemented a few mods to my 1996 metro (grill block, lowered, advanced timing, 125/15 donuts spare's for rear and fully gutted 1600lbs)
So, i'm not thinking about.... i am going to use 2 140/90/15's for the front, (24.9'') compared to the 155/80/13's (22.6'') on now. The wheels i am using are off any mid nineties Honda accord spare 15X4 10LBS, 4X114.3. The tires I will be putting on them are rated at 800lbs at 41 psi which is fine for my 500lb x2 front.
I drive around 80 miles to work so pulse and glide is not in my cards, 70-75 is though. Here's the kicker the tires i am using will be hard compound motorcycle tire's 36 bucks each....... I'll let you know how they hold up.
oh yeah this will be combined with a 1993 1.3 swift tranny and a camback.

Frank Lee · 11-06-2009, 11:46 PM

Nope- you didn't learn to run donuts here.

Bike tires either.

Hell, you're in the middle of classic VW country, you must be swimming in skinny 15s.

Christ · 11-07-2009, 12:59 AM

I have to second that. If your new tires aren't rated for highway service, or have "D" anywhere in the size, or are rounded in the tread area, I can't advocate using them.

That said, I've put bike tires on cars. They weren't street cars primarily, though, so I can't attest to the true handling characteristics of them.

155/80/13 will work fine on your Metro.

CapriRacer · 11-07-2009, 09:42 AM

First, motorcycle and car tires have different bead diameters! In other words: A 15" tire is not always 15.000" - and in this case, they are enough different that they are not interchangeable.

Sure, you could probably get them mounted - and maybe you'll get the tires to survive, but there is a risk and the consequences can be quite severe!

Besides, there are plenty of car tires that are much more suited for what you are trying to accomplish - and you can actually get tires that have improved Rolling Resistance as a feature - something NOT a consideration on M/C tires.

bgd73 · 11-08-2009, 11:24 PM

I made this mistake just once, with tall 13s. I mean real tall. I learned they were for some sort of mobile home

the deal was a bit too good, should have paid attention. 55mph was weeble wobbles thumping jumping ... and still not losing, it was an awd sube. the experiment taught me that 15s are damn good. It would be hard to find 15s not in highway rating.

nvygw171 · 11-11-2009, 05:09 PM

Quote:

Originally Posted by CapriRacer

First, motorcycle and car tires have different bead diameters! In other words: A 15" tire is not always 15.000" - and in this case, they are enough different that they are not interchangeable.

As far as bead diameters on cycle tires in realation to car wheels, google "dark side tires". Unless there is some wheel to rim spacer these guy's are running and not mentioning it....

nvygw171 · 11-11-2009, 05:25 PM

Quote:

Originally Posted by Frank Lee

Nope- you didn't learn to run donuts here.

Bike tires either.

Hell, you're in the middle of classic VW country, you must be swimming in skinny 15s.

False
http://ecomodder.com/forum/showthrea...80-a-3176.html
True on the bike tires, not saying that it hasn't been brought up here just that i came up with the idea on my own thank you.

As far as the V-dub stuff goes i looked into that and decided that 80 bucks a pop for tires that are .5" taller didn't really make sense....to me

Christ · 11-11-2009, 10:34 PM

Quote:

Originally Posted by nvygw171

As far as bead diameters on cycle tires in realation to car wheels, google "dark side tires". Unless there is some wheel to rim spacer these guy's are running and not mentioning it....

Capri is actually right, to my knowledge, but there are different motorcycle tires that change this. Normally, they shouldn't fit because tires that are designed for tubes don't have as much of a sealing bead on them, IIRC, and that changes the inner diameter of the tire's bead.

I've personally seen motorcycle tires mounted on car rims, and I've personally mounted a car tire on a motorcycle, so I know that it will work.

Frank Lee · 11-11-2009, 11:36 PM

Quote:

Originally Posted by nvygw171

False
http://ecomodder.com/forum/showthrea...80-a-3176.html
True on the bike tires, not saying that it hasn't been brought up here just that i came up with the idea on my own thank you.

As far as the V-dub stuff goes i looked into that and decided that 80 bucks a pop for tires that are .5" taller didn't really make sense....to me

Those are ELECTRIC cars. Think of the speed and distance duty cycles of those electric cars then think of the demands placed on their tires.

Consensus is for faster cars donuts are no good. There's no advantage anyway but several disadvantages.

VW tires: 135, 145, 165, 185 SR 15- those are all a hella lot more than +.5"dia.

Last year I was looking for 165s and found em for $25 ea at Pep Boys.

roflwaffle · 11-12-2009, 02:29 AM

Have you tested the donuts RR in order to see if there's a significant difference between them and a small LRR tire? Besides, at best you could pick up a few mpg at 70-75mph if you cut the rolling resistance in half compared to whatever is on there now. If you cut the drag coefficient in half like basjoos did, you'll gain 20+mpg at 70-75mph, and there won't be any worries about undesirable operation.