Chris Harris: M135i Obliterates RS3

[MexicoCityM3]

This little hatch has been getting rave reviews everywhere. Now Chris Harris chimes in:

http://youtu.be/2xwecTp91-o

I know the design is.....ahem...."controversial"....but other than that this seems like a baby 1M. Here it is arriving this month at 15K below what my car cost, about even with an Audi S3 (keep in mind the above comparison is vs. the much more expensive RS3).

It's looking like a fantastic Q-car.

[850CSi]

38MPG!?

[MexicoCityM3]

38MPG!?

Imperial, about 31 US MPG, still impressive.

[sportyaccordy]

Imperial, about 31 US MPG, still impressive.

Yah, just saw this (subscribed)

This is good, M cars for the common man, somewhat. I wonder if we will get this or the regular 1 hatch at all here.

[MexicoCityM3]

Yah, just saw this (subscribed)

This is good, M cars for the common man, somewhat. I wonder if we will get this or the regular 1 hatch at all here.

Not the hatch, but you will get something similar in the form of a M235i coupe.
However, I like the practicality + ultra performance of the hatch.

[MexicoCityM3]

I just checked and it is finally up on BMW Mexico configurator (http://www.bmw.com.mx/mx/es/general/ecom_configurator/configurador_ecom.html). It's coming in both 3 and 5 door variants.

I'd only add the better stereo and the adaptive dampers (and keep the auto tranny). Comes in at US$51,100. This is a seriously good performance & all around option down here. After watching the video I got curious and started reading the reviews on the European & Australian rags. Every single one has nothing but praise for the car.

[Cookie Monster]

I just checked and it is finally up on BMW Mexico configurator (http://www.bmw.com.mx/mx/es/general/ecom_configurator/configurador_ecom.html). It's coming in both 3 and 5 door variants.

I'd only add the better stereo and the adaptive dampers (and keep the auto tranny). Comes in at US$51,100. This is a seriously good performance & all around option down here. After watching the video I got curious and started reading the reviews on the European & Australian rags. Every single one has nothing but praise for the car.

wat

[850CSi]

wat

[S204STi]

Friend of mine is thinking about a 135i.  I wish I he could buy one of these instead...  but still, great cars.

[MexicoCityM3]

Friend of mine is thinking about a 135i.  I wish I he could buy one of these instead...  but still, great cars.

135i is fine but I think this is an improvement, independent of body style, this new generation has some fundamental improvements. It seems to understeer a lot less (from the reviews) + the new auto tranny is superb + the usual improved gadgetry.

[r0tor]

The RS3 and the TT-RS both seem to blindingly fast on the track yet "dull" in test reviews.  I have to wonder if these cars are just exceptionally deceptive in their speed and the understeer comment just are a result of flat out entering the corners too fast.

The tester can shrug off the lap time difference all he wants, but the bmw is on summer performance tires.and.the Audi is not.  Thats huge.  He proved in a straight line they are about equal.  So if the Audi handling is that horrid, how foes it overcome the huge tire gap and convincingly beat the bmw?

[MX793]

300+ HP RWD car with an open diff?  No thanks.

[sportyaccordy]

The RS3 and the TT-RS both seem to blindingly fast on the track yet "dull" in test reviews.  I have to wonder if these cars are just exceptionally deceptive in their speed and the understeer comment just are a result of flat out entering the corners too fast.

The tester can shrug off the lap time difference all he wants, but the bmw is on summer performance tires.and.the Audi is not.  Thats huge.  He proved in a straight line they are about equal.  So if the Audi handling is that horrid, how foes it overcome the huge tire gap and convincingly beat the bmw?

If a car is deceptive in its speed its probably boring to drive even at the limit. But the Audi, like all Audis save the R8, is probably notoriously nose heavy and thus does have some legit understeer issues. I also don't think this one had the active rear diff, which helps correct it. Understeer sucks because it punishes the driver for pushing the car, which is the whole point of a hot hatch. So I can def see why dude didnt enjoy it. As for why the Audi was faster, I think it had a good clip more power, and the advantage of AWD to blast out of turn exits- esp the tighter stuff.

Faster != better

300+ HP RWD car with an open diff?  No thanks.

[cawimmer430]

300+ HP RWD car with an open diff?  No thanks.

Maybe this will change your mind. 

[r0tor]

The drag race proves it doesn't have any better acceleration anywhere in the powerband.

With an awd car you can chuck it into a turn way too fast and usually nothing will happen but it plows.  Thats not understeer, thats over driving.  If you can't turn from a neutral gas/brake position or can't put power down early do to the front end pushing wide - thats true understeer.  The lap times seem to indicate to me the car is easily over driven because it's incredibly forgiving - ot that it has terminal understeer.

[MX793]

Maybe this will change your mind. 

No, not really.  I have a 300+ hp RWD car.  If the roads are wet and I put my foot down in 3rd gear @ 30 mph (which is ~2100 RPM in my car), the car will start to accelerate normally without any slip but as soon as it hits 3500 RPM, you can feel the back end starting to get squirrely as BOTH rear tires (I have a limited slip diff) start to break loose.  BMW's 3.0L Turbo has more torque than my car and at equally low, if not lower, RPMs.  I suspect the TCS light will be getting a workout in wet roads unless you are very judicious with your right foot.

[cawimmer430]

No, not really.  I have a 300+ hp RWD car.  If the roads are wet and I put my foot down in 3rd gear @ 30 mph (which is ~2100 RPM in my car), the car will start to accelerate normally without any slip but as soon as it hits 3500 RPM, you can feel the back end starting to get squirrely as BOTH rear tires (I have a limited slip diff) start to break loose.  BMW's 3.0L Turbo has more torque than my car and at equally low, if not lower, RPMs.  I suspect the TCS light will be getting a workout in wet roads unless you are very judicious with your right foot.

I have the same problem with my car and I only have 143-horsepower. 

I'm no fan of the new 1-Series, but with the M-Body Kit like in the photo I posted, they do look "interesting".

[MX793]

I have the same problem with my car and I only have 143-horsepower.  

I'm no fan of the new 1-Series, but with the M-Body Kit like in the photo I posted, they do look "interesting".

Your 143 hp car will break both rear tires loose under power at 55 mph in 3rd gear without using any drivetrain "shock" techniques (clutch popping or similar)?  I don't think so.  I had a 155 hp RWD car, with open diff, that wouldn't do that.  Romping on it in 2nd gear in the rain, especially while cornering, it would one wheel peal, but out of 2nd gear you weren't going to break the tires loose simply by applying throttle unless you were on snow/ice (wouldn't break loose in the wet).

[MexicoCityM3]

The M135i has an e-diff that is independent of the DSC. It will brake the spinning wheel even when dsc is off to transfer power to the other end. I won't argue here about it's effectiveness (a true LSD is of course better) but many reviews I read mention that it works pretty well.

There is a comment in the video by harris about diffs that intrigued me. He says an LSD can actually increase initial understeer. How does that work?

And Wimmer, really do you have traction problems on dry surfaces? Can't believe it.

[MX793]

The M135i has an e-diff that is independent of the DSC. It will brake the spinning wheel even when dsc is off to transfer power to the other end. I won't argue here about it's effectiveness (a true LSD is of course better) but many reviews I read mention that it works pretty well.

There is a comment in the video by harris about diffs that intrigued me. He says an LSD can actually increase initial understeer. How does that work?

And Wimmer, really do you have traction problems on dry surfaces? Can't believe it.

With a limit slip, the rear axle will tend to want to behave like a solid axle up until the point where the difference in forces on the inside and outside tires exceeds the slip threshold of the differential.  This tends to make a car not want to turn/rotate as the inside and outside tires fight each other (the outside wants to spin faster, the inside slower).  It has a similar effect as when a stability control system drags the outside rear brake to try to curb oversteer.  With an open diff, the inside and outside tires are free to spin at different speeds, so there is no resistance to rotation from the rear axle.

[Raza]

Maybe this will change your mind. 

In that M trim, it actually does look decent.

[sportyaccordy]

The drag race proves it doesn't have any better acceleration anywhere in the powerband.

With an awd car you can chuck it into a turn way too fast and usually nothing will happen but it plows.  Thats not understeer, thats over driving.  If you can't turn from a neutral gas/brake position or can't put power down early do to the front end pushing wide - thats true understeer.  The lap times seem to indicate to me the car is easily over driven because it's incredibly forgiving - ot that it has terminal understeer.

Audis are notorious for power-on understeer (aka true understeer). This thing is a 350HP Golf R.... I would be surprised if it DIDN'T understeer.

There is a comment in the video by harris about diffs that intrigued me. He says an LSD can actually increase initial understeer. How does that work?

I see it like this. Torque split requirements change for tight turns and sweepers. An LSD tuned for tight turns would make the rear end squirrely at high speed. It would make the car rotate more than the driver wanted to. On the flip side, an LSD tuned for long sweepers and high speed turns wouldn't rotate the car enough at low speed tight turns. IOW understeer. So there is an art to getting it right. I remember the Quaife in my second Accord literally pulling the car into and through turns when I gave it gas. I never got to track it so I didn't get to find out how it would do at high speed sweepers fully loaded. It worked great though but I could see that being a problem in a RWD car.

In any case e-diffs and even this brake driven system have an advantage in their all-speed/condition adaptability.

[Raza]

The M135i has an e-diff that is independent of the DSC. It will brake the spinning wheel even when dsc is off to transfer power to the other end. I won't argue here about it's effectiveness (a true LSD is of course better) but many reviews I read mention that it works pretty well.

There is a comment in the video by harris about diffs that intrigued me. He says an LSD can actually increase initial understeer. How does that work?

And Wimmer, really do you have traction problems on dry surfaces? Can't believe it.

Lotus said the same thing when they added an LSD as an option for the Elise, and recommended it only for buyers who will be taking their car to a track, since it's supposed to be of greater benefit there than on the road.  I'm not sure of the reason either.

[MexicoCityM3]

Thanks for the explanation.

I think the LSD on recent M cars like my cars works a bit differently. It's supposed to variably apply locking force in proprtion to the speed difference between the wheels. This would make it not influence turn-in, right, acting like an open diff then?

Or is all that about variable M differential just BMW marketing-speak?

The latest M5/6 have a different system too that is electronically controled somehow.

[MX793]

Thanks for the explanation.

I think the LSD on recent M cars like my cars works a bit differently. It's supposed to variably apply locking force in proprtion to the speed difference between the wheels. This would make it not influence turn-in, right, acting like an open diff then?

Or is all that about variable M differential just BMW marketing-speak?

The latest M5/6 have a different system too that is electronically controled somehow.

Not all limited slips are created equal.  There are a number of different types that behave differently.  Some have a fixed torque split value under all conditions, some 3 set values (powered, neutral, braking), some are speed-sensing, some are torque-sensing.

[r0tor]

Audis are notorious for power-on understeer (aka true understeer). This thing is a 350HP Golf R.... I would be surprised if it DIDN'T understeer.

Power on understeer would contradict you previous explanation of how the Audi is faster because it put power down better coming out of a turn...

[850CSi]

Power on understeer would contradict you previous explanation of how the Audi is faster because it put power down better coming out of a turn...

Not necessarily...

[850CSi]

300+ HP RWD car with an open diff?  No thanks.

I've never really lamented the lack of a slippy diff on my car, but I'd also want one with that much power.

[cawimmer430]

Your 143 hp car will break both rear tires loose under power at 55 mph in 3rd gear without using any drivetrain "shock" techniques (clutch popping or similar)?  I don't think so.  I had a 155 hp RWD car, with open diff, that wouldn't do that.  Romping on it in 2nd gear in the rain, especially while cornering, it would one wheel peal, but out of 2nd gear you weren't going to break the tires loose simply by applying throttle unless you were on snow/ice (wouldn't break loose in the wet).

No, none of that. My back tends to break out in wet/winter conditions even with gentle steering input. See my post to Hector below.

Maybe I misunderstood your initial post. I thankfully don't have to worry about "extra power" in my car. 

And Wimmer, really do you have traction problems on dry surfaces? Can't believe it.

Not in the dry (unless it's a sandy surface), in the wet and winter. Do you get the 1er 5-Door E87 in Mexico? It's not a particularly fun car to drive in the wet/winter as the back has a tendency to break out even at low speed even with gentle steering input. This has happened to me a couple of times in the city in the winter (twice in the rain in the summer). With time I've become accustomed to the cars handling in these conditions but it still happens.

[hotrodalex]

Stability control kills any rear end action in my car, so it's fine in the winter.