SenorChispa
Well-known member
- Joined
- Sep 17, 2013
- Messages
- 45
Does anyone know why chevy chose to put different width tires on the back vs the front? (195 vs 185)? Do they not believe in tire rotation?
I believe they did it due to the fact that there is more weight in the rear of the car due to the placement of the battery pack.SenorChispa said:Does anyone know why chevy chose to put different width tires on the back vs the front? (195 vs 185)? Do they not believe in tire rotation?
markcmann said:I believe they did it due to the fact that there is more weight in the rear of the car due to the placement of the battery pack.
SenorChispa said:markcmann said:I believe they did it due to the fact that there is more weight in the rear of the car due to the placement of the battery pack.
That would be a very reasonable explanation except that the weight distribution is nearly 50/50 according to the Car and Driver review. And the first time somebody rotates their tires then the size difference is backwards, which defeats the purpose of having different sizes.
Rotation is not optional if you want to get full life out of the tires. The fronts will wear out twice as fast as the back. Rotating left to right instead of front to back is a no-no.
I just can't imagine what Chevy was thinking with this.
Nashco said:I expect they wanted the rears wider for handling purposes. Your 50/50 comment makes sense in a static world, but the tires are sharing weight very disproportionately dynamically, especially with struts in front and a beam axle in the rear. The rear inner tire in hard cornering carries very little weight, usually.
Bryce
buickanddeere said:Is there enough room on the front to mount 195mm tires up there? I prefer the same size all around for rotation. Plus we usually put new tires on the front and move the 1/2 worn out tires to the back.
Any different in the rim width and offset front vs. back ?
Nashco said:For future reference, this is the stock Spark EV wheel specs.
Front
15x6.0
ET45
Part number 95024486
Rear
15x6.5
ET54
Part number 95024487
Nashco said:buickanddeere said:Is there enough room on the front to mount 195mm tires up there? I prefer the same size all around for rotation. Plus we usually put new tires on the front and move the 1/2 worn out tires to the back.
Any different in the rim width and offset front vs. back ?
As has been mentioned many times on this forum, the front and rear wheels are different sizes and can't be rotated front to rear!
http://mychevysparkev.com/forum/viewtopic.php?f=10&t=3496
Nashco said:For future reference, this is the stock Spark EV wheel specs.
Front
15x6.0
ET45
Part number 95024486
Rear
15x6.5
ET54
Part number 95024487
I have put a LOT of work into getting the same size wheels and tires front to rear (for autocrossing purposes), and I intend to document how this can be done soon. However, I can tell you now that it is neither cheap nor easy to accomplish. By far, the path of least resistance is rotating side to side instead of front to rear and using the stock wheels with stock sized tires.
Bryce
buickanddeere said:There would have to be some awful close clearances if a 1/4" more tire rubs on something. There must be some difference in the rim offset front to rear ? Can't be a whole lot if the front and rears follow the same track?
Nashco said:buickanddeere said:There would have to be some awful close clearances if a 1/4" more tire rubs on something. There must be some difference in the rim offset front to rear ? Can't be a whole lot if the front and rears follow the same track?
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.
The clearances are extremely tight, the tightest of any factory car I've ever worked with. They're so tight that the car has rolled fender lips in the rear and almost no fender lips in the front from the factory. Don't take my word for it, go look at your own car. When in jounce (like hitting a bump) the stock tires are extremely close. Again, don't take my word for it, remove your springs and try it, or load a bunch of weight in the back until the suspension sags.
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
gmarcucio said:Actually the suspension along with unibody reinforcement is upgraded on the Spark EV from the ICE version because of the torque involved.
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