Trailer Tires on a Geo Metro ...

[orangebychoice]

I know I will get some heat for this - but I've been doing some research (and didn't see any small cars running them here - just trucks) and I think it might work! They have stiffer sidewalls (for lower rolling resistance) and are way cheaper. Here's the points I thought of.

Pros:
I drive 55-65 max anyway so speed isn't an issue
I think the ride couldn't get much worse
The load rating on a trailer tire is higher then a passenger car
Easier to find 12" size in a trailer tire

Cons:
Trailer tires (supposedly) don't have the same quality regulations
Trailer tires on the front could make steering difficult at low speed
Trailer tires say 'for trailer use only' and could be an insurance liability

Okay, so flame on - why isn't everybody doing this??

[mcrews]

welcome.
There must be 10-15 extensive threads here on taller tires. Did you search?
What sixe do you currently have?
what size are you looking at?

[MTXA]

Assuming you are looking at radial because bias is a whole nother can of worms.

The stiffer sidewall will negatively effect braking and cornering.

Trailer tires are not manufactured for wet conditions.

Trailer tires are notoriously difficult to balance.

I've pondered the same thing. I'd give it a try for a car that sees low speed urban driving or largely rural roads under 55mph. I don't think I would feel safe in faster congested traffic.

[CapriRacer]

Mcrews,

The OP (orange) is talking about TRAILER tires, not "taller" tires. Tires that go on a vehicle you pull behind a tow vehicle.

Orange,

First, let me clear up a couple of mis-conceptions:

Rolling resistance is much, much more about tread compound than anything else. Sidewall stiffness is such a minor player you can pretty much ignore it.

Trailer tires are done differently than car tires. Since trailer tires don't have to steer or drive the vehicle, the affects of side forces and torsional forces allow the tires to be rated at higher load carrying capacities than car tires. Put another way, if you compare the load rating of trailer tires with any tire designed for a powered vehicle, you'll notice the trailer tire is rated for a higher load carrying capacity.

Notice that trailer tires are designated differently than car tires. They either have a different size nomenclature (like 4.80-12, or 20.5X8.0-10) or they have letters in front of or behind the size to indicate the type of service the tire was designed for (like ST205/75R15).

Because of the service, trailer tires aren't concerned much about traction or treadwear. Many trailers don't have brakes. Also, trailer tires tend to get old before the tread is worn off. As a result, the tread compound in these tires isn't designed with those properties in mind.

What is the major design factor? Cost!! That means that the tread compound - the thing that is going to have the largest affect on rolling resistance - is going to be a low cost, low tech rubber. Rolling resistance is not even in the consideration.

So assuming you could properly navigate through tire size and load rating, you'd find that a trailer tire will have a major deficiency in either traction, treadwear or rolling resistance (or more than one.)

That's why trailer tires aren't used on cars and trucks.

- and since the demand for these types of tires is small compared to cars and trucks, trailer tires are made by what I would call 3rd tier tire manufacturers - not the major tire manufacturers (with one exception, which is an interesting study in itself). Needless to say, there are issues with these tires.

[MTXA]

When I wrote that I would give it a try, it would be based on three things

1. 12" car tires appear to becoming obsolete. Trailer tires may become the only choice

2. A large percentage of my driving is on flat, straight, under 35 mph, lightly traveled roads and I'm a pretty conservative driver

3. Nobody has ever accused me of being wrapped real tight

[Ryland]

The only car I've driven with trailer tires was a Honda N600 and with trailer tires on it had lousy handling and that was in a car that seldom is driven over 40mph, switching to real car tires made the car driveable! it drives and handles like a real car, at least as good as my parents Geo Metro!
Real tires made it feel like you had control going around corners, small bumps in the road didn't make you feel like you were going to die and you had traction! it was amazing what real car tires can do, I'm not sure I would use a trailer tire even as a spare tire if I had to go over 25mph, granted that car has 10" rims, so there was only one option we could find for real tires for it and they were back ordered for a few months, but I'm pretty sure that if we could find 10" car tires that you can find more then a few 12" tire options.
Your other option of course is to get 13" geo metro rims.

[mcrews]

my bad.
it does belong in unicorn,

[orangebychoice]

Thanks for the help! I can see the pros and cons - and really it seems like a catch 22. I'll stay with regular tires (they're not THAT hard to find, just harder) ... either way I think I can find safer ways ecomod. I'm working on doing a belly pan - so I think I'll just head in that direction for now! Make sure to check out the pictures of the new Geo when I get them up!

[justme1969]

Been there did it Had no choice but liked the results.
94?xfi I had in mid 90s I ran may pops lost a tire near Yuma Arizona.
Other side on rear had big blisters had no spare due to large speaker in that locale.
Hardware place had 2 that were a little narrow but would fit the Geo wheels.
He mounted them with hand tools no balancing and moved good tire up front.
Put them on the back. worked awesome! 50 psi never had probblem.
rear tires outlived set of Invictas I put on front a year later.
Geo rear brakes are an afterthought. the narrow tire with z stripe tread pattern cut through standing water better than the invictas with enginne weight and wind down force on them could clearly see the tread through front tire marking behind car.
I tried them on front 1x not good scarey sliding stop that I thought would never end and found out a xfi Geo could now burn out!
Much harder compound too hard for front end.

[oil pan 4]

12'' car tires are a dead rim size, 13'' car tires are a dieing rim size.