Braking Performance

[Ex_Stig]

I came out of an '11 M3 sedan into the M5 so feel free to PM me any questions. I actually think the M5 brakes are fantastic compared to the M3. Especially when you consider the extra weight.

[emmfive]

Originally Posted by RealStig

At 40-50 mph, if I slam the brakes, the car takes a lot longer to stop than my M3 and the difference is extremely visible and made me very uncomfortable.

Your assessment surprises me. In city situations I feel dam near invincible, in terms of agility acceleration and braking. I did several runs on the autobahn getting up to 130-150, then hard braking down to 60-80, repeated several times in a short time period. My impression was all amazement at the impressive stopping power.

[B-1Pilot]

Originally Posted by RealStig

I have test driven the M5 again today, for the 4th time! This was mostly for braking, which was something I didn't properly test before. I can tell you that compared to my good old E90 M3, the braking is really not that great. At 40-50 mph, if I slam the brakes, the car takes a lot longer to stop than my M3 and the difference is extremely visible and made me very uncomfortable. Yes in city driving with casual turns, it is acceptable, but if you really want to drive the car hard, 4300 lbs shows its weight and it is quite noticeable.

Now remember that what I am comparing this car against is a 2011 model M3, the new M3 is lighter and has much better brakes and tires, so the difference will most likely be more pronounced.

That being said, if anyone drives the M5 the way I did today, they probably have bought the wrong car to begin with. I think they are two totally different cars. So don't take what I said the wrong way.

So I drove a 2011 M3 cp today and then my car immediately afterward. I had read your post so I paid attention to the braking... To me both cars brake about the same from same speeds within about 7-8 feet of each other to a stop. Not sure why you aren't getting the similar braking performance that the rest of us get with an M5.

[RealStig]

I may actually know why I didn't have great braking performance today. My car has bridgestone blizzaks on. It was 17F outside today. M5 had Michelin PSS. So it may have been a factor of the temperature plus the tire.

That being said, I am not going to lie here, the car is extremely heavy and you feel that weight the most when you are breaking. In the M3, I'm almost 100% certain that I will always break before a certain hypothetical threshold X feet away from my position and I always hit my target. With the M5, I found myself getting always nervous. It was like the weight of the car was always working against me and it was pretty obvious. I'm not sure if this was because of the tires alone because ABS wasn't kicking in and there was no sliding or anything. It was the pads working overtime to compensate the weight of the car.

As someone else said, "considering the weight..." the brakes perform phenomenal - which is very true. But when you compare it to the 600 lbs lighter M3, you immediately feel the difference. I'd say of all the areas where the weight is an issue (handling, acceleration, and braking), braking is probably the only concern to me.

This car also did not have CCBs, not sure if this is relevant.

[Ex_Stig]

CCBs would have been much worse in that cold temperature.

As for the comparison... You'll adjust and get more comfortable within a week of driving the M5.

[thebishman]

Originally Posted by RealStig

I have test driven the M5 again today, for the 4th time! This was mostly for braking, which was something I didn't properly test before. I can tell you that compared to my good old E90 M3, the braking is really not that great. At 40-50 mph, if I slam the brakes, the car takes a lot longer to stop than my M3 and the difference is extremely visible and made me very uncomfortable. Yes in city driving with casual turns, it is acceptable, but if you really want to drive the car hard, 4300 lbs shows its weight and it is quite noticeable.

Now remember that what I am comparing this car against is a 2011 model M3, the new M3 is lighter and has much better brakes and tires, so the difference will most likely be more pronounced.

That being said, if anyone drives the M5 the way I did today, they probably have bought the wrong car to begin with. I think they are two totally different cars. So don't take what I said the wrong way.

A couple of things to remember: One is the weight difference which works against the M5 obviously, and Two, if the M5 is on the lot then it is doubtful that the brakes have been bedded in in any way; hence are still 'green'. This can have a profound effect on stopping distance until the brakes have either been bedded in correctly or at the least have had quite a few heat cycles thru' them.

Personally I think the car stops incredibly well on the street but believe the European press that on the track the brakes will experience fade within a few laps. This can be mitigated with better brake fluid and better, (i.e. track oriented), pads, but I'm not sure even today if higher performance pads are available.

Bish

[RealStig]

Originally Posted by thebishman

A couple of things to remember: One is the weight difference which works against the M5 obviously, and Two, if the M5 is on the lot then it is doubtful that the brakes have been bedded in in any way; hence are still 'green'. This can have a profound effect on stopping distance until the brakes have either been bedded in correctly or at the least have had quite a few heat cycles thru' them.

Personally I think the car stops incredibly well on the street but believe the European press that on the track the brakes will experience fade within a few laps. This can be mitigated with better brake fluid and better, (i.e. track oriented), pads, but I'm not sure even today if higher performance pads are available.

Bish

Brake fading is something else and is not a concern for me. All M cars suffer from the same problem, and in the case of M5, it's nothing new. I don't track my cars so I don't really care about this.

I have test driven yet another M5 last weekend (probably last in my area) and this one seemed to have brake much much better than the one before. Both cars had the steel brakes, both cars had the competition package. Both cars had around 50 miles in the odometer. The only difference was the previous test drive took place when it was 14-15F outside and this weekend it was 50F. That being said, these were not "hard braking" but rather slowing the car down to a complete stop without actually slamming the brakes. I always thought the tires come into picture when you slam the brakes and ABS is enabled and only then having the right tires will make a big difference.

[M5 RAG]

Originally Posted by RealStig

Brake fading is something else and is not a concern for me. All M cars suffer from the same problem, and in the case of M5, it's nothing new. I don't track my cars so I don't really care about this.

I have test driven yet another M5 last weekend (probably last in my area) and this one seemed to have brake much much better than the one before. Both cars had the steel brakes, both cars had the competition package. Both cars had around 50 miles in the odometer. The only difference was the previous test drive took place when it was 14-15F outside and this weekend it was 50F. That being said, these were not "hard braking" but rather slowing the car down to a complete stop without actually slamming the brakes. I always thought the tires come into picture when you slam the brakes and ABS is enabled and only then having the right tires will make a big difference.

There is no way the brakes would be close to optimum performance if we are talking about cars with 50 miles on them from new, think this is the issue here.

[RealStig]

Originally Posted by M5 RAG

There is no way the brakes would be close to optimum performance if we are talking about cars with 50 miles on them from new, think this is the issue here.

Then how do you explain two different cars performing very differently? The only difference was the weather temperature.

[signes]

Operator error...

[M5 RAG]

Originally Posted by RealStig

Then how do you explain two different cars performing very differently? The only difference was the weather temperature.

I couldn't tell you but its not a fair comparison to judge a cars braking performance when the pads are not even bedded in, at 50 miles they're not even close.

[thebishman]

Originally Posted by RealStig

Brake fading is something else and is not a concern for me. All M cars suffer from the same problem, and in the case of M5, it's nothing new. I don't track my cars so I don't really care about this.

I have test driven yet another M5 last weekend (probably last in my area) and this one seemed to have brake much much better than the one before. Both cars had the steel brakes, both cars had the competition package. Both cars had around 50 miles in the odometer. The only difference was the previous test drive took place when it was 14-15F outside and this weekend it was 50F. That being said, these were not "hard braking" but rather slowing the car down to a complete stop without actually slamming the brakes. I always thought the tires come into picture when you slam the brakes and ABS is enabled and only then having the right tires will make a big difference.

All I can tell you is that in a street scenario, my M5 when braked hard will literally throw you into the self belt and hold you there as you come, rapidly, to a stop even from very high speeds. This is with both the Michelin PSS and my Sottozero winters; (just not quite so much).
Bish