Mixed size stock tires?

[Nashco]

I see no indication on the tires themselves that they are unidirectional (like "this side out" or an arrow indicating direction of travel) but the spark advisor says they are in fact unidirectional tires.

The tires are not unidirectional. The tires can (and should) be rotated left to right, but not front to rear. Sounds like you got some bad information from the spark advisor.

Bryce

 

[romorris2342]

Well you say they won't last 36K miles. But you do say I can rotate left to right. I'll try once again to confirm that left to right (did twice - chevy service and then chevy that this isn't do'able) but going directly to the tire manufacturer re directionality this time. If yes, I'll rotate as you say - plus hope they last my lease term - which is 30k miles total, no the the 36k you were assuming. I'll hope that 18% or so less means they don't wear out. If they don't, everything else is moot. I've never owned a tire that wouldn't go 30K as far as I can remember, but I've never had these tiny ones either.

 

[romorris2342]

Right you are Nashco. These are not unidirectional tires per the manufacturer. As my chevy dealer will not rotate them as I directed, I won't go there anymore. That's pretty much the only service it requires. As Chevrolet itself doesn't know this simplest of detail (for them) either, I really can't be using them at all once I turn the car in.

Left to right rotation it is.

I really never intended to go Chevy but as we needed a 2nd electric car and I saw the $119/month 10K/year lease, I made an exception. I thought it
was a typo at the time but called anyway. Living with the constant screw up's is hard. The price doesn't make it much easier I suppose.

I see no indication on the tires themselves that they are unidirectional (like "this side out" or an arrow indicating direction of travel) but the spark advisor says they are in fact unidirectional tires.

The tires are not unidirectional. The tires can (and should) be rotated left to right, but not front to rear. Sounds like you got some bad information from the spark advisor.

Bryce

 

[nozferatu]

Well you say they won't last 36K miles. But you do say I can rotate left to right. I'll try once again to confirm that left to right (did twice - chevy service and then chevy that this isn't do'able) but going directly to the tire manufacturer re directionality this time. If yes, I'll rotate as you say - plus hope they last my lease term - which is 30k miles total, no the the 36k you were assuming. I'll hope that 18% or so less means they don't wear out. If they don't, everything else is moot. I've never owned a tire that wouldn't go 30K as far as I can remember, but I've never had these tiny ones either.

The stock tires on these cars are not very good....in anything.

 

[Electricbowtie]

stock tires are horrible. Just trashed the front tires at 9800 miles and got non-LRR Firestone Firehawk instead. Much better tire so far and not much range loss.

 

[romorris2342]

stock tires are horrible. Just trashed the front tires at 9800 miles and got non-LRR Firestone Firehawk instead. Much better tire so far and not much range loss.

Because you hated how they performed

Or because they were worn out ?

I'm not really picky regarding performance or a 'driving experience'.

 

[Nashco]

I'm not really picky regarding performance or a 'driving experience'.

Tire performance and safety are directly linked. If you aren't picky about performance, are you saying you don't care about safety either? Traction=control, and I'm pretty particular about controlling the 3000 pound machine that I am in charge of. The factory tires sacrifice in all metrics except rolling resistance, it seems, and arguably road noise.

Bryce

 

[Pegasus]

Did you read my post? The offset IS different, as I showed above. The front wheels have 45mm offset, the rears have 54mm offset. If the rears are installed in the front, the spokes hit the calipers.

Then how the heck does mine work when my Chevy dealer rotated front-to-back?? (Evidenced by them forgetting to reset the TPMS.)

 

[romorris2342]

Because they didn't do what they told you they did. Misinformation *abounds* at Chevy. Both Chevy itself
and Keys Chevy (Van Nuys CA) had me convinced no tire rotation of any kind could be done. Left
to right is the proper. Front to back is impossible. This matches the Owner's Manual and once one realizes
the stock tires are non-directional tires.

They may have started and then reversed themselves ... or went left to right. Now you don't know and
that's worse than the job not being done at all as in my case. I went to Americas tire after Chevy failed
at this drooling-at-the-mouth trivial thing. I spent 10 hours screwing around with Chevy and Americas
tire did the job for free in-and-out in 10 minutes. Told me to *never* go to the dealer, come there.
I'm taking that advice. It doesn't matter that "Chevy Complete Care" is free, the dealer has no interest
in providing that to you and will thwart you at every step.

Did you read my post? The offset IS different, as I showed above. The front wheels have 45mm offset, the rears have 54mm offset. If the rears are installed in the front, the spokes hit the calipers.

Then how the heck does mine work when my Chevy dealer rotated front-to-back?? (Evidenced by them forgetting to reset the TPMS.)

 

[nozferatu]

stock tires are horrible. Just trashed the front tires at 9800 miles and got non-LRR Firestone Firehawk instead. Much better tire so far and not much range loss.

Because you hated how they performed

Or because they were worn out ?

I'm not really picky regarding performance or a 'driving experience'.

For me it's both. And I'll extend this to the stock suspension of this car which I find hideously dangerous...for me. It contributes to the lousy grip this car has.

 

[Electricbowtie]

stock tires are horrible. Just trashed the front tires at 9800 miles and got non-LRR Firestone Firehawk instead. Much better tire so far and not much range loss.

Because you hated how they performed

Or because they were worn out ?

I'm not really picky regarding performance or a 'driving experience'.

The front tires were already worn out and nearly bald and traction control was kicking on around most freeway ramps.

 

[NomadMac]

stock tires are horrible. Just trashed the front tires at 9800 miles and got non-LRR Firestone Firehawk instead. Much better tire so far and not much range loss.

Because you hated how they performed

Or because they were worn out ?

I'm not really picky regarding performance or a 'driving experience'.

For me it's both. And I'll extend this to the stock suspension of this car which I find hideously dangerous...for me. It contributes to the lousy grip this car has.

The Spark loves to tootle along at 7/10ths but it quickly becomes 10/10ths in the blink of an eye...namely, when it comes to a corner.

 

[nozferatu]

The Spark loves to tootle along at 7/10ths but it quickly becomes 10/10ths in the blink of an eye...namely, when it comes to a corner.

LOL...agreed.

 

[nj1266]

You CAN bolt the front tires on to the rear without any drama. So, if you really want the same size wheels and tires all around, it's easy as long as you use four of the smaller front wheel and tire combinations (185 on a 15x6 et45). I didn't see any rubbing when I tested it on my car, but proceed with caution as I didn't drive it this way. This isn't cheap, of course, because you would have to buy two new wheels...and it's not really any advantage.

Bryce

Removing the stagger is an advantage. The stagger (rear wide tires and wheels) is designed to induce under steer. Same size tires/wheels front and rear reduces under steer and makes the car turn in better. I did that on my old S2000 which was staggered by design. OEMs stagger wheels/tires to induce under steer because it is easier to deal with an under steering car than an over steering car. I prefer a neutral car. I think 15x6 45 offset with a good set of rubber might make the car handle better. Another bonus is that you can rotate the tires.

One question to you: What size wheels does the regular Spark come with?

 

[Jeeman0]

So, if you leave the front rims where they are (correct offset) and try to put 185/60 tires will they rub somewhere? I really want to put on Michelin tires on the front, but that is the only size that is close.

And I'm thinking the 195/55s are too wide?

Bryce...you seem to be the resident expert on technical things, I'd like to hear what do you think too?

 

[Nashco]

I just had my factory tires dismounted and remounted with the factory (rear) 195s mounted on the front wheels and factory (front) 185s mounted on the rear wheels. I haven't driven with them yet, but a stationary test fit in the shop looks like there may be some very minor rubbing between the inside of the tire and the chassis at full steering lock.

I'll have more feedback after I do a test drive. Keep in mind that I have a modified suspension with different alignment settings (camber!)and (lowered) ride height such that even the factory wheel and tire combination had this same minor rubbing. It rubs *just enough* to squeak a bit and polish the paint off the chassis, so it's really barely touching and only at full lock.

With that said, I think a 185/60 or 195/55 in front would probably be fine with stock suspension. It really depends on the exact tire as some brands run a little big while others run a little small. Any good tire store will do a test fit with one if you're borderline (as our cars are) and if there's a rub you can pull the offending tire off and only be out a few bucks for mount and dismount.

FWIW, I'm doing this experiment because after about 4000 miles my fronts were already (!) getting close to the wear bars. They're really efficient and quiet tires, and my wife is commuting in my car for a bit, so I wanted to get my race tires off and give her some range and quieter ride without buying another pair of tires. The rears looked great, so hopefully this dismount/remount rotation can stretch me out to at least 12k miles before buying new rubber.

Bryce

 

[JoeSchmoe]

I wouldn't encourage anyone put the skinny tires in the rear. Square all around is one thing...skinnier tires at the back is another. Not that there are any hard fast rules when talking about such a small difference in section width, but I'm just sayin'...

 

[Nashco]

I wouldn't encourage anyone put the skinny tires in the rear. Square all around is one thing...skinnier tires at the back is another. Not that there are any hard fast rules when talking about such a small difference in section width, but I'm just sayin'...

Based on what reasoning? As you said, the difference in the front and rear tires is extremely small. If you go square all around (which I have done), it's a tiny tick away from the factory configuration. If you put the big tires on the smaller wheels (and vice versa), you're one more tiny tick away from the factory configuration. Why is the first tiny tick ok, but the second tiny tick is not?

Bryce

 

[JoeSchmoe]

I'd characterize reversing the OEM stagger as a step in the wrong direction versus the right direction. I could say that you're increasing the likelihood of oversteer and you wouldn't be able to refute that based on contact patch shape alone. We are still talking about small differences but why go there? Why even advocate it to people who may not be "skilled" drivers or "car people"? We'll probably just have to disagree on the matter, but people should know that there is an opposing opinion.

 

[Nashco]

If I could get this turd of a stability control system to allow some oversteer, I'd be in heaven! Opinions that differ are great, that's how I learn new things. Your opinion is interesting and different than mine...why is that your opinion? Do you believe this car is extremely sensitive to tire changes, on the knife edge of oversteer, or ...???

Bryce