Torque Steer

[SanDiego]

How's everybody doing with the Spark's torque steer? It's something anybody who drives the car becomes aware of in short order. I noticed it the first time out on a test drive and decided it was tolerable. A Tesla owner asked me about it, not knowing about torque steer; he said he was totally spooked by it when he drove the car. My wife has really felt it when riding in the back seat (I suppose the effect is amplified back there). I know if I'm going to floor the go pedal I want to have both hands on the wheel, whether it's from a stop or on the Interstate with a full power passing maneuver.

I find the side-to-side "sawing" from the torque steer (back and forth from left to right) strange, because ever since my first front-wheel-drive car (a 1963 MG 1100) I've experienced torque steer pulling the car in just one direction. Why would the Spark pull back and forth like this?

The best hint at an explanation I've found is from a Motor Trend first drive report last November: "Torque steer manifests in a relatively smooth, straight line, but there's apparent counteracting damping in place (presumably software-based) as the steering wheel does slow heaves, not twitches."

That's a pretty good way to describe the sensation: "slow heaves". And it's interesting that "apparently" Chevy used software-based damping to control things; it hadn't occurred to me that these days onboard computers can be used for just about everything. The notable Consumer Reports first drive report, where they were so enthusiastic about the car, stated "It takes some getting used to use the throttle's touchiness to avoid torque steer." That's a grammatically odd sentence, but yeah, it points out that we can avoid the torque steer by being more moderate with the go pedal!

The Spark is not the only electric car exhibiting torque steer, of course. The more torque delivered to the front wheels, the bigger the issue. I know Tony mentioned his Rav4/Tesla shows a good measure of it.

 

[rbroders]

Yes, it is very annoying. Seems to be worse if you are accelerating and turning at the same time.

I think it could be a function of wheel slip. When you lose traction, on one side the car pulls one way or another. Magnified by the cars automatic power reduction when a wheel starts spinning.

I am seriously considering new tires to help solve this problem. The Yokohama S. drive's look good. I can't find UTQG ratings for our Bridgestone ECOPIA EP150s to compare though.

--Bob

 

[SanDiego]

Bob, that's a very interesting idea to change tires. I've already concluded that we will have to replace the stock front tires at or before the expiration of our 3 year / 36,000 mile lease; no way the tread will last. So why not replace them now, with more functional tires? It's clear, as you are concluding, that the stock tires (especially on the front) are not living up to the handling/traction potential of the car. The stock tires can go back on to satisfy the tread depth requirements at the end of the lease. I'll be interested to hear what you come up with, and I'll try to research some too. Thanks.

 

[Nealr]

I remember years ago Saab built the Viggen. Part of the sales package were driving
lessons to deal with the torque steer. I floored our Spark and at about 30mph the tires
were breaking loose and the torque steer was causing some weaving. Not a very assuring
feeling so I backed off.

 

[SenorChispa]

I don't own a spark yet (coming soon), but I noticed this torque steer effect big time in my first test drive. I was in sport mode, flooring it as I entered a curving on-ramp to the freeway. It started darting left and right until I let off the gas. I figured out quickly what was happening and adjusted my driving, but that first wobble was very disconcerting. I wonder what would happen if I tried the same manuever with electronic stability control turned off? If ESC is overcompensating for the torque steer and causing the seesaw motion, turning it off should prevent the seesaw and you should get wheelspin instead. Anyone wanna try it and report back?

 

[fengshui]

Interestingly, I haven't noticed the torque steer on my Spark EV. I've spent plenty of time under heavy accelleration, but I just don't notice it. Perhaps it varies?

I do notice some loss of power and traction issues when powering out of a curve sometime, but traction control tends to kill the power and get me back going pretty quickly.

 

[rbroders]

Just an update to this thread. I installed Yokohama S. Drive tires and my torque steer problems have almost completely disappeared

--Bob

 

[Pegasus]

Just an update to this thread. I installed Yokohama S. Drive tires and my torque steer problems have almost completely disappeared

I'd like to know how they affect your range though. At what pressure do you run them?

 

[rbroders]

I don't know how much the range changes. Fortunately my daily driving is less than 20mi per day (good cause my 10,000mile per year lease works out to 27.3 miles per day). I just crank the A/C, put it in Sport and punch it!

Even though all the torque is supposedly available at zero rpm, this car seems a bit sluggish until it hits 5-10mph and then it really goes...

I run the S. Drives at 35psi, same as the Ecopias.

--Bob

 

[ecilopaveht]

Even though all the torque is supposedly available at zero rpm, this car seems a bit sluggish until it hits 5-10mph and then it really goes...


--Bob

This is software related, I also have a Volt and it does the same thing. On the GM-VOLT web site a few have got into hacking the software of the Volt, to provide a 5.5 sec 0-60 time! Just imagine what could be done with this car!

http://www.youtube.com/watch?v=hA4fLSuvkk8&feature=c4-overview&list=UURGgwPKoHeWZlBsYpM02wVw

 

[drchocotaco]

Just an update to this thread. I installed Yokohama S. Drive tires and my torque steer problems have almost completely disappeared

--Bob

I was considering buying some sport tires, swapping them and holding onto the OEMs to swap back near the end of the lease. Where did you buy the Yoko's? How much did they run you?

 

[iletric]

...and are they low resistance tires?

 

[ecilopaveht]

...and are they low resistance tires?

These are the street performance tires. They should provide more fun, but less overall distance. especially if you really use those tires like they are meant to be used. :lol:

 

[Anonymous]

Just an update to this thread. I installed Yokohama S. Drive tires and my torque steer problems have almost completely disappeared

--Bob

Did you install the Yokohama S tires only in front or all four?

 

[SanDiego]

I wonder how the Yokohama tires are wearing on the front. ??

At 9,000 miles the original Bridgestone tires are almost down to the wear bars (while the rear tires still look new).

 

[nozferatu]

I wonder how the Yokohama tires are wearing on the front. ??

At 9,000 miles the original Bridgestone tires are almost down to the wear bars (while the rear tires still look new).

Seriously?? In 9K miles? are you doing burns every time you leave the light? lol

 

[TonyWilliams]

I wonder how the Yokohama tires are wearing on the front. ??

At 9,000 miles the original Bridgestone tires are almost down to the wear bars (while the rear tires still look new).

Seriously?? In 9K miles? are you doing burns every time you leave the light? lol

If they are the Bridgestone Ecopia tires, those are known for short life.

 

[tigger19687]

I wonder how the Yokohama tires are wearing on the front. ??

At 9,000 miles the original Bridgestone tires are almost down to the wear bars (while the rear tires still look new).

Seriously?? In 9K miles? are you doing burns every time you leave the light? lol

If they are the Bridgestone Ecopia tires, those are known for short life.

If that is the case, what is the Warranty on them?
If they don't make that mileage, can't you get a refund or something ?

You would think they would put a good tire on these little cars

 

[SanDiego]

I wonder how the Yokohama tires are wearing on the front. ??

At 9,000 miles the original Bridgestone tires are almost down to the wear bars (while the rear tires still look new).

If they are the Bridgestone Ecopia tires, those are known for short life.

If that is the case, what is the Warranty on them?
If they don't make that mileage, can't you get a refund or something ?

You would think they would put a good tire on these little cars

Bridgestone states that "...original equipment tires on new vehicles have no mileage warranty." (See http://www.bridgestonetire.com/customer-care/tire-warranties/supplemental-mileage)

True, Bridgestone Ecopia tires are not known for lasting long, but Prius owners seem to uniformly report pretty good longevity. I think the Ecopia tires on the rear of the Spark EV may well last for our 36K lease term. But the front tires are surely undersized for the weight they carry, and yes burn outs with them take a toll. We don't do burnouts, but if you punch it, especially around corners, they will chirp every time. I'm sure if I always hyper-miled they might last twice as long as they are lasting.

Sure would like to know how current users find the Yokohama S to be holding up. If they handle a lot better, I'm pretty sure they wouldn't be chirping all the time the way the Ecopia's do, and they'd have to get better wear. (As an aside, it would be so great if this car could have been rear wheel drive with the chunky rear tires it has; that would make it a hotter racer and maybe get better tire wear oh well.)

Another factor, I theorize, may be that we drive so much on San Diego highways. I have a motorcycle that is not capable of burning rubber, but the Bridgestone OEM rear tire (which always wears much faster than the front tire) wore out in a few thousand miles, while a guy in Portland got maybe 4 times the wear that I did. As we tried out Pirelli and then Michelin, he and I both got better wear, but he still always beat me by a ratio of 4 to 1. Our roads are hotter; are the surfaces also literally rougher?

 

[TonyWilliams]

I wore out a set of Bridgestone Ecopia tires on the LEAF in under 25,000 miles. No burn outs, but chirping the tires in sharp turn acceleration is normal.

I replaced them with Michelin MXM tires, and those were quiet and smooth.