Pull to Right Stops After Switching Wheels / Tires

My Civic is pretty much off the road right now, so I want to work on what I can while waiting for a new engine.

I decided to put my all-seasons back on the car. My prior setup was 15x7 +41 Enkei RPF1's with 195/50-15 Dunlop Direzza Start Spec ZII's.  I wouldn't describe the handling as great with this setup, the car would always pull to the right unless the steering wheel was held straight ahead. The steering was pretty "numb" feeling and didn't inspire a lot of confidence. I switched back to the stock steelies with 175/70-13 all seasons and was shocked at the handling difference. The pull to the right all but disappeared, and the steering became light with tons of feedback. So much more enjoyable to drive. I was not expecting this.

Anyone have any idea why the "better" wheel / tire setup would handle worse than the "worse" setup. I don't remember the ZII's originally handling like this. I can only think of two rationales for this: 1) I have an alignment / wheel bearing issue that is eating through the faster wearing ZII's quicker or 2) the ZII's have never been rotated left to right, only front to back, and perhaps they got used to running that way? The ZII's only have a few thousand miles on them... Last time the car was aligned it had 1/16" toe-out on the front and zero on the rear which I don't imagine would be wearing tires that fast. Does anyone have any ideas or suggestions of things to look at? 

Tires can have pulls.  Actually, all tires have a degree of pull, it's just that most of the time it is so minor that you don't notice it.

We just got a new balancer in at work that does road force AND lateral force measurement.  You can balance a set of four tires and swap them around so that pull is minimized.  Neat stuff.  That's what $37k buys you nowadays...

More commonly, a tire pull is because the tire is worn cone shaped.  If you have heavy wear on the inside or outside, when it is rolling down the road it is like trying to roll a styrofoam coffee cup.  If both tires on the front are worn identically, it cancels out.

Additionally, if you have one new tire on the front and one used, the vehicle will almost always pull toward the new tire.

I know that a helical (torsen) diff will pull to one side under power and the other under decel if the overall diameter is different left to right. Mismatched pressures can do it.

I'm betting on your tires are crap. In my experience pulling is almost always caused by tire pressure differentials or conicity. Maybe brake drag. Your alignment would have to be really wacky to cause pulling.

It could be exacerbated if the scrub radius is increased with the Enkeis. 

You are mis-using the term "Handling".  The hot rod tires will go around corners faster, with the compromise being tram lining and darting and pulling.  The smaller tires will always drive straight down the road more nicely, but that's not handling.  It's comfort, or stability, or something.

If you want to diagnose the tires, switch side to side and see if the pull follows the tires.

Streetwiseguy said:

You are mis-using the term "Handling".  The hot rod tires will go around corners faster, with the compromise being tram lining and darting and pulling.  The smaller tires will always drive straight down the road more nicely, but that's not handling.  It's comfort, or stability, or something.

Handling is how well the car does what you want it to, cornering speed is grip.  They're two separate things.

Generally speaking, tall narrow tires handle better, but short fat ones grip better.

I can (and have) build a car that can have very good grip and absolutely scary handling.  Negative camber and soft tires can get you a silly amount of grip as long as you can drive as absolutely smoothly as possible and the road is pool-table smooth.   (Isn't the basis for getting good times in Stock class autocross?)

A chassis that does what you want it to do, and doesn't do things that you don't want it to do, is a bit more difficult.  That is where legends are made which gets spoken of in glowing terms.

I did consider that the scrub radius may be off with the Enkei's, but +41 is only like 4 mm off from the stock offset as far as I'm aware, that doesn't seem like it'd be a very noticeable change. Due to my Dunlop's being directional, is it unwise to swap sides causing them to be going the wrong direction? My understanding is that would only become a problem in rain. 

If it is indeed the tires that are screwed up, can I just take them to the tire place and have them swap the tires onto the opposite side wheel? I was leaning towards trying this but didn't know if it was a suspension problem or something. 

Thanks for the responses guys.

You could swap them side to side to test if that changes the pull.  If it doesn't, it's probably a combination of the wider tires wanting to follow road crown more and with some toe out and a slight scrub radius change, it might be enough to feel it as a significant pull, while the small tires don't impart enough force to notice the pull. 

Okay, got around to putting my Star Specs back on the car this evening. I put them on "backwards" so the right side became the left side and vice-versa.

As a result I'm pretty sure the issue is the tires. On a flat road (which there are very few here in Colorado) the car tracks totally straight, if the road is cambered to the left it will go to the left, if it's cambered to the right it goes to the right. On a lot of roads it still seems like it's "favoring" the right, but I assume that's just from the road crown. I have no idea if it's normal or not, but the tires seem to pick up any imperfection in the road and make a lunge towards it. You really have to be holding onto the steering wheel. They still seem a little less precise than the 175/70-13 all seasons that were on it previously, but maybe that's just how it is. All in all, I think it's probably fine.

So does this mean the tires are trashed or can I just have the tire place swap the tires onto the opposite wheels? Is there any way to prevent this from happening again, aside from changing my alignment? Thanks everyone.

I'd check the toe first. you may need a little more toe in. An ET of 41mm shouldn't be an issue, neither should a 195 mm section width. Now, having said that, I do notice that my Miata is easier to drive with standard wheels and 185 tires than it is with 205s on 7" wheels. It's sensitive to changes in camber, caster, and scrub radius. It's not bad handling, just different and less relaxed . The steering feel is lighter on the OEM wheels and tires.

I had the same issue with my Civic and the Star Specs/Rota's that came on it - always pulled right.  I rotated the rears to the front and it did the same thing - didn't swap side to side due to the directional nature of the "tread".  Swapped to the OE steelies and all-season Falkens for the winter and it drives dead straight.  The Dunlops are OLD, so I assumed they were the problem, glad to see this confirmed.

I've had a tire with a loose band cause a steering pull. It was super annoying and hard to diagnose, because alignment always comes back fine. Outer half of tire had slightly larger diameter than the inner half, adding phantom camber to the car. I didn't notice the band until it started vibrating and I took it off to inspect. After replacing tires, it drove straight as an arrow.

DeadSkunk said:

I'd check the toe first. you may need a little more toe in. An ET of 41mm shouldn't be an issue, neither should a 195 mm section width. Now, having said that, I do notice that my Miata is easier to drive with standard wheels and 185 tires than it is with 205s on 7" wheels. It's sensitive to changes in camber, caster, and scrub radius. It's not bad handling, just different and less relaxed . The steering feel is lighter on the OEM wheels and tires.

Last time I had the car aligned it had 1/16" toe-out on the front and zero toe on the rear. That doesn't seem like a lot to me, but I'm not sure. Agree on the car feeling less relaxed, I don't really mind the "frantic" nature it has on these wheels, but I don't like the numb on-center feeling I get with them. I don't know if that's wear related or not, I didn't notice it on the all-seasons.

Is it likely the tires are garbage or could it just the result of excessive wear on the right side? I don't want to pitch the tires if they're salvageable, but I also don't want to force myself to drive on crap tires if that's what they are. 

Try resetting it to 0 toe up front and see if that helps.  It might make it less twitchy and less prone to pulling.  

I think it’s both- tires AND alignment. 

Your alignment settings are off (just a little), and more pronounced with the bigger tires. This has caused wear in the Star Specs, which magnified the problem. 

Replacing the tires will fix the problem, but it will come back if you don’t also get the alignment right. 

My $.02

I was under the impression that FWD cars should run a lot of front toe-out, or does this mostly refer to auto-cross/track-only cars? I'd like this car to become more and more of a fun-only car, but money and time may interfere with these plans. 

The car rotates really well, but perhaps that's not worth the pulling and twitchiness in a straight line. I'll have a go with changing the alignment once I get my engine swapped. I'm concerned I'll screw the alignment up, but I have some toe-plates, and perhaps if I'm patient I'll be able to get it right. 

Occasionally I've noticed that it will dart to the left when letting off throttle (in a straight line), so perhaps there's another issue going on with the suspension. Everything is new though, so I'll probably start with the alignment I suppose. 

Toe out will definitely make it turn in more sharply and quickly, but it comes at the expense of dartiness and reduced stability in a straight line.  Every car / driver / tires / usage combination has a limit of how much toe out will be tolerable.  

Had the same experience when I installed my new centerline wheels and bfg tires on my car. Before I changed the wheels/tires, the alignment was perfect. Getting a new alignment solved the issue.