what happens when you have different size tires?

[SandrA9810]

if rear tires are smaller than the front, what issues will you have?

 

[MICKEY88]

if rear tires are smaller than the front, what issues will you have?

I believe it will cause handling/stability issues,

why do you have different size tires

 

[Squirlz]

Instability. Possibility of spinning and loss of control. Go with what the manufacturer recommends.

 

[C.Ann]

It's dangerous - and will also have a detrimental impact on your gas mileage.. Not a good idea..

 

[gisgt]

I'm assuming you mean different rim sizes as opposed to widths. If it's only an inch of difference, you shouldn't have any problems. The larger ones should be on the back, though. Any larger than that on a street car could have issues. If it's width your asking about, no problem at all. What kind of car is it??

 

[SandrA9810]

it's a 95 mercury villager. It's the same size rims, just different tires.

driver front
215/75/r15
passenger front
205/75/r15

driver rear
195/65/r15
passenger rear
196/65/r15

The two front tires are brand new (well one is a little older than the other) but only like a few months old.
The rear tires, I went to a used tire place. My rears were worn down to the wire, and I needed to make a trip back to miami. I've never had any issues buying used before, and knew I needed something that could handle the 400-500mile drive. They told me it wouldn't be an issue to have the smaller tires, so I agreed to 50$ for the two tires.

Now, my brakes are failing because the ABS is trying to engage because it's trying to stop the rear tires from spinning so fast. Once the car disengages the ABS system (and light turns on) I don't have a problem stopping. I trust my mechanics, and just a week prior to buying these tires I had an oil change done, and brakes inspected.
The rear brakes had a spring or something break in it, which they fixed. And the front brakes are about a year old. That car probably only has had about 2,000 miles driven on it in the past couple of years. I went yesterday to the mechanics, and they pulled the tires off again, nothing wrong with the brakes. Talked with the mechanic, and he asked if I did anything with the tires, and I said, yeah, the rears are a bit smaller. He said, that's your problem.

Now the used tire place won't do anything about it, and of course "their" mechanic says there shouldn't be any problems.

 

[gisgt]

I did the calculations (Section Width / 25.4 x (Aspect Ratio / 100) x 2 + Wheel Diameter = Tire Diameter) for the sizes you gave me and it looks like the difference is big enough to be causing the ABS to kick in.
Front 215/75/R15 = 27.696850
Front 205/75R15 = 27.106299
Rear 195/65R15 = 24.980314
It's actually the slower rotating wheels that are confusing it, it thinks they're sliding. The good news is it won't damage anything by activating the ABS unnecessarily. The ABS doesn't do anything but pulsate the brakes faster than you could by pumping the pedal. If you want to keep using them, you could just pull the fuse on the ABS. Then you'd be able to stop normally, without it kicking in. The tire shop is probably unhelpful because there's nothing actually wrong with the tires, but for what it's worth I think 50 bucks is a pretty good deal even if you only used them to get home & toss them in the garage to use as spares.

 

[MICKEY88]

I personally would advise against pulling the fuse.. ABS exists for a reason, to prevent skidding in hard breaaking situations

 

[Disnydad]

Find out what the manufacturer has for specs. My wifes Cadillac SRX has different size front and rear tires, but that's what Cadillac specs are for that model vehicle.

 

[SandrA9810]

205/75/R15 is whats on the driver side door.

There's just no way to even afford to put tires on. I should've just walked away, i didn't like the guy much at all. At least if a tire blows, i know how to put a spare on. I can't do anything about the brakes not working, especially when they're not bad.

So frustrated.

 

[jen0610]

I personally would advise against pulling the fuse.. ABS exists for a reason, to prevent skidding in hard breaaking situations

Don't know for sure or not, but wouldn't tampering with an installed safety system put you into a position of some serious legal trouble. IF you were to cause an accident with a personal injury suit and it was found to be caused by the ABS not being in working order, that would end up costing you a whole lot more than putting 4 of the same tires on the car.

I just would do whatever it takes to make sure I have tires on the car that are all the same size, unless the cars specs call for something else.