Out of spec rear wheels toe

[inquirer]

I had new struts installed and at the same time an alignment job done.

For some reason the mechanic set the rear total toe at 0.0 mm with the normal range being 0.7 mm to 2.8 mm (mean value 1.8 mm)
left toe at 0.1 mm (normal: 0.4 mm – 1.4 mm, mean 0.9 mm)
right toe at -0.1 mm (normal: 0.4 mm – 1.4 mm, mean 0.9 mm)

and the left rear camber at -0° 50' (normal range: -1°25' to -0°25', mean: -0°55')
and the right rear camber at -0° 59' (normal range: -1°25' to -0°25', mean: -0°55')

Obviously, the rear toe is out of spec. I have consulted 3 other alignment shops about that, with the 2 saying that the difference is so small that there won't be any problems like uneven tire wear and the 1 suggesting to realign the wheels.

Whose right? Is this small deviation going to have any measurable effects (like uneven tire wear) or should I ignore it?

 

[skyactiv]

I'd live with it.

 

[HankHill]

What type of car is it? For example, in my Taurus you would never even notice it.. In my old BMW with the sport suspension, I'm pretty sure I would feel it. I am sensitive to the point where in the BMW it would drive me nuts.

 

[meep]

You might actually like it. If I’m not mistaken, it will be more willing to let the rear exhibit less under steer.

 

[mightymousetech]

You might actually like it. If I’m not mistaken, it will be more willing to let the rear exhibit less under steer.

Huh? That’s not how it works. Understeer is understeer, and zero rear toe will significantly reduce understeer.

That rear toe is not good. Setting rear toe to zero will create an unstable vehicle. Will never feel stable and relaxed when driving in a straight line.

 

[HankHill]

Huh? That’s not how it works. Understeer is understeer, and zero rear toe will significantly reduce understeer.

That rear toe is not good. Setting rear toe to zero will create an unstable vehicle. Will never feel stable and relaxed when driving in a straight line.

This

 

[inquirer]

What type of car is it? For example, in my Taurus you would never even notice it.. In my old BMW with the sport suspension, I'm pretty sure I would feel it. I am sensitive to the point where in the BMW it would drive me nuts.

It's the last Mitsubishi Lancer, FWD.

Huh? That’s not how it works. Understeer is understeer, and zero rear toe will significantly reduce understeer.

That rear toe is not good. Setting rear toe to zero will create an unstable vehicle. Will never feel stable and relaxed when driving in a straight line.

I'm wondering what the mechanic had in mind, because he obviously set to 0 mm on purpose. Are there any supposed benefits?

 

[mightymousetech]

It's the last Mitsubishi Lancer, FWD.



I'm wondering what the mechanic had in mind, because he obviously set to 0 mm on purpose. Are there any supposed benefits?

It will increase the tendency to oversteer, so the car will rotate easier if you are planning on autoxing. It allows easier mid corner lift throttle oversteer. Can get a little “exciting” on the street if not expecting it. It can reduce outer edge tread wear if that is an issue on the car.

I must say though, have never seen a rack set up to show toe in mm’s instead of degrees or minutes. Do you have a copy of the printout?

 

[inquirer]

It will increase the tendency to oversteer, so the car will rotate easier if you are planning on autoxing. It allows easier mid corner lift throttle oversteer. Can get a little “exciting” on the street if not expecting it. It can reduce outer edge tread wear if that is an issue on the car.

I must say though, have never seen a rack set up to show toe in mm’s instead of degrees or minutes. Do you have a copy of the printout?

Yes I have a copy. It states toe in mm. Mitsubishi's manual in pages 47 and 48 also uses mm. The machine used for the alignment was a relatively old one of the Corghi brand.

I guess that tread wear is a combination of the toe and camber angles, as well as the type of the roads the car is usually driven on and the driving style.

 

[mightymousetech]

Yes I have a copy. It states toe in mm. Mitsubishi's manual in pages 47 and 48 also uses mm. The machine used for the alignment was a relatively old one of the Corghi brand.

I guess that tread wear is a combination of the toe and camber angles, as well as the type of the roads the car is usually driven on and the driving style.

Toe is 90% of tire wear. When toe is significantly off, you are literally dragging the tire sideways down the road.

If that is how Mitsu measures toe, and this are the specs, I would probably set rear toe at 1 mm positive toe (toe in) per wheel for a total toe of 2 mm.

 

[meep]

Huh? That’s not how it works. Understeer is understeer, and zero rear toe will significantly reduce understeer.

That rear toe is not good. Setting rear toe to zero will create an unstable vehicle. Will never feel stable and relaxed when driving in a straight line.

not saying I’d want to do it on a street car, but the zero toe will let the rear come around quicker since it’s not countering with toe. Say you steer left. Weight shifts to the right. With less toe in on the right rear, it will ever so slightly drift rightward, inducing oversteer to the left. You are still correct…. it is less stable, but to a small degree it might be ok.

 

[meep]

It will increase the tendency to oversteer, so the car will rotate easier if you are planning on autoxing. It allows easier mid corner lift throttle oversteer. Can get a little “exciting” on the street if not expecting it. It can reduce outer edge tread wear if that is an issue on the car.

I must say though, have never seen a rack set up to show toe in mm’s instead of degrees or minutes. Do you have a copy of the printout?

I thought so. I’d think that 0 toe would almost be ok, except potentially while braking. If they pull back and out during hard braking, that might be a little hairy.