[IANNUZZI]

Actually r&t has the Ctsv hitting 150mph in 17.8s and a trap speed of 126mph. That’s more in line with its advertised power however for sure rwd and 30-profile tires are holding back acceleration numbers ....

[vtknight]

Originally Posted by Alpine535Msport

It has to do with it being rear wheel drive. The better a car can put down all that power with proper traction the better it is capable of utilizing all the high horsepower and torque more effective to produce quicker acceleration times. This is why AWD makes the M5, E63 produce the numbers it did.

You are correct - in a couple of reviews they put the M5 to RWD and ran a mid 11 second 1/4 mile lol. The AWD is a massive factor.

[vtknight]

Originally Posted by Bönz

Very true. Also if history has taught us anything, the Germans under-report their horsepower. Plus, the turbo engines with variable cam phasing produce peak torque earlier and hold it flatter through the RPM range; whereas the supercharged GM engine's torque production peaks later and rolls off sooner. It's the area under the torque curve the moves the car.

I would say this is also correct. Motortrend did a comparison of the F10 and my earlier lease the E63S and they both were higher than stated. The E63S much higher in fact for that generation. In the end it's all math in order to make the numbers we are seeing here...there is no magic.

[vtknight]

Originally Posted by Bönz

While gearing certainly impacts acceleration, all these cars make 4 shifts through the 1/4 mile.

Yes - and they are extremely close in performance. That said - with 8 versus 9 gears - those four gears/gearing will be different - enough for the 1/4 mile level tenth of a second difference we are seeing in the test. The Merc finally comes back at the 150 MPH mark - so maybe the closer ratios up too make that difference as it needed to make up ground.

[vtknight]

Originally Posted by IANNUZZI

Actually r&t has the Ctsv hitting 150mph in 17.8s and a trap speed of 126mph. That’s more in line with its advertised power however for sure rwd and 30-profile tires are holding back acceleration numbers ....

Having the C7Z - I can tell you it underperformed stock. Many/most have been running 125-128 MPH depending on DA stock at the track. There is enormous downforce (Cd) for sure - but there are other issues with the first gen direct injection as well as stock Tune from GM. The CTSV has always been slower.
Heat soak is a major issue with the Uber tiny blower (1.74L).

I had to move to a Procharger to get away from all of these issues and to finally make some power and performance with the car.

[DocWeatherington]

Originally Posted by Alpine535Msport

4th place: Porsche Panamera Turbo
3rd place: Cadillac CTS-V
2nd place: Mercedes-AMG E63 S 4Matic
1st place: BMW M5

Bring on the Comp Pack

[dhirm5]

C&D back to loving the M5 -- I guess BMW decided to start paying again...

J/K but if someone happens to be on the inside, it sure feels that way. For a while Audi won every comparo.. speaking of which, where is the RS7 in this test?

[IANNUZZI]

Originally Posted by vtknight

Having the C7Z - I can tell you it underperformed stock. Many/most have been running 125-128 MPH depending on DA stock at the track. There is enormous downforce (Cd) for sure - but there are other issues with the first gen direct injection as well as stock Tune from GM. The CTSV has always been slower.
Heat soak is a major issue with the Uber tiny blower (1.74L).

I had to move to a Procharger to get away from all of these issues and to finally make some power and performance with the car.

GM was able to meet their power goals with the smaller supercharger. For sure it is not as friendly to the modded crowd as it becomes inefficient at higher boost, however the smaller supercharger uses less power to spin and builds boost faster. Many enthusiasts such as yourself , and those that buy this type of car, are ultimately concerned less with efficiency and fuel economy as much as they are about performance, so they will not mind going to an aftermarket supercharger. However, unless serious rubber is used, much of the extra power at low to medium speeds goes up in smoke....

[vtknight]

Originally Posted by IANNUZZI

GM was able to meet their power goals with the smaller supercharger. For sure it is not as friendly to the modded crowd as it becomes inefficient at higher boost, however the smaller supercharger uses less power to spin and builds boost faster. Many enthusiasts such as yourself , and those that buy this type of car, are ultimately concerned less with efficiency and fuel economy as much as they are about performance, so they will not mind going to an aftermarket supercharger. However, unless serious rubber is used, much of the extra power at low to medium speeds goes up in smoke....

GM tried to make an NA car as all Z06's had been. They could not make it work - likely power as well as poor fuel economy. So I could almost see their minds light up - "hey let's use FI - but really really tiny FI". This worked from an innocuous point of view as you literally could not hear it - it sounded and felt NA.

That said - that quicker spinning - more "efficient" super charger is a roots type. The literal worst supercharger for heat production. So spinning faster only helps that along. Add the poor engine bay circulation and it is the perfect storm for heat soak. The new ZL1 has 11 coolers for example.

Direct injection is another issue - which is why the new ZR1 has both DI and port injection added. Poor aero rounds everything out.

Traction is always an issue for any RWD car. But interestingly - the Procharger with much more power - actually hooks better as the real power comes on like a turbo (mid-top) versus a roots SC which is all low end torque.

So - it actually worked out. Costly - but worked out lol.

[IANNUZZI]

Originally Posted by vtknight

GM tried to make an NA car as all Z06's had been. They could not make it work - likely power as well as poor fuel economy. So I could almost see their minds light up - "hey let's use FI - but really really tiny FI". This worked from an innocuous point of view as you literally could not hear it - it sounded and felt NA.

That said - that quicker spinning - more "efficient" super charger is a roots type. The literal worst supercharger for heat production. So spinning faster only helps that along. Add the poor engine bay circulation and it is the perfect storm for heat soak. The new ZL1 has 11 coolers for example.

Direct injection is another issue - which is why the new ZR1 has both DI and port injection added. Poor aero rounds everything out.

Traction is always an issue for any RWD car. But interestingly - the Procharger with much more power - actually hooks better as the real power comes on like a turbo (mid-top) versus a roots SC which is all low end torque.

So - it actually worked out. Costly - but worked out lol.

It still blows my mind that they have 11 coolers on the ZO6 to deal with the heat.

It blows my mind even more that they do not work well to control heat, especially on previous years....

[vtknight]

Originally Posted by IANNUZZI

It still blows my mind that they have 11 coolers on the ZO6 to deal with the heat.

It blows my mind even more that they do not work well to control heat, especially on previous years....

The Z06 doesn't have the 11 coolers I'm afraid...the ZL1 does (and the ZR1 13 - although it's a much bigger blower - 2.65).

The fact they needed to add 11 coolers shows the scope and urgency of the problem. The fact it works is great. As we didn't get it for or cars however - not so much.

I did add the secondary GM rad to mine - but the intense heat soak and poor engine bay circulation just delayed the inevitable. On top of that I had a much larger primary rad, billet thermostat, oil cooler and intercooler. All not enough.

At least they got it right the second time around...

[Stealth7]

The octane issue, if true, could be significant. I will read the whole article shortly. However, if each car was tested based on its approved min. octane, then in a state such as CA where we only have 91 as premium (not counting rare and expensive 100), the BMW, Porsche and Cadillac may be down on power compared to the E63s. Further, adding 93 to a car tuned for 91 does not typically add power. Since the few advantages the M5 has from the chart above over the E63s are razor thin (including storage space??!!), the 91 v. 93 issue might make a meaningful difference in terms of real world performance in 91 octane states. Of course, all of these cars are fast for their categories, and none is a race car.

I am in the market for either a M5 or an E63s so these are interesting times and I really appreciate the new owner feedback!

[MTHX]

Originally Posted by Stealth7

The octane issue, if true, could be significant. I will read the whole article shortly. However, if each car was tested based on its approved min. octane, then in a state such as CA where we only have 91 as premium (not counting rare and expensive 100), the BMW, Porsche and Cadillac may be down on power compared to the E63s. Further, adding 93 to a car tuned for 91 does not typically add power. Since the few advantages the M5 has from the chart above over the E63s are razor thin (including storage space??!!), the 91 v. 93 issue might make a meaningful difference in terms of real world performance in 91 octane states. Of course, all of these cars are fast for their categories, and none is a race car.

I am in the market for either a M5 or an E63s so these are interesting times and I really appreciate the new owner feedback!

seems that new m5 use 91 octane minimum but recommend 93 octane ....

https://www.bimmerpost.com/forums/at...mentid=1678386


hummm .....

probably the rason why the us version as more hp then european one (+ 8 hp)

[frankchn]

Originally Posted by MTHX

probably the rason why the us version as more hp then european one (+ 8 hp)

The engine is rated in metric horsepower in Europe, while it is rated in imperial horsepower in the US.

600 PS (metric horsepower) = 591.8 hp.

[MTHX]

Originally Posted by frankchn

The engine is rated in metric horsepower in Europe, while it is rated in imperial horsepower in the US.

600 PS (metric horsepower) = 591.8 hp.

the european version is rated at 441.3 kW the us one is 447 kW

https://www.autoevolution.com/cars/b...-xdrive-600-hp

my VIN give me 447 kW not 441 like you can see on many review from europe or australia.

but the point was more about the recommended 93 octane ...

[frankchn]

Originally Posted by MTHX

the european version is rated at 441.3 kW the us one is 447 kW

https://www.autoevolution.com/cars/b...-xdrive-600-hp

my VIN give me 447 kW not 441 like european model

Ah, I see the 447 kW number on my VIN as well. Is there a European M5 VIN I can look up? (I found one prototype car VIN -- G499957 which had a 441 kW hp rating, but that car was also built in late 2016 and had a different model code as well (JF01 rather than JF0C))

It seems like the global press release mentions 441 kW / 600 hp in the specifications, and the BMW USA press release mentions 600 hp.

I wonder if someone who was converting units converted 600 US/imperial hp to kW when entering specifications for the US model into the BMW vehicle information database, but they should have converted 600 PS to kW instead (which would result in 441 kW).

That seems more likely than a higher tune for the US market, especially since AKI 93 gas is equivalent to RON 98 gas, which is widely available in Europe as well, so I assume the recommendation in Europe will be RON 95 minimum and RON 98 recommended? Unless of course, there are other difference in fuel quality that will cause BMW to tune the engines differently.

[Stealth7]

The question is did the 93 octane cars get tested on 93 octane or 91 octane? If they were tested on 91 octane then their computers would slightly decrease the performance. On the other hand, if the 93 octane cars were tested on 93 , then they had the full advertised power-- power that would not be available in 91 octane States To the 93 octane cars.

[vtknight]

Originally Posted by Stealth7

The question is did the 93 octane cars get tested on 93 octane or 91 octane? If they were tested on 91 octane then their computers would slightly decrease the performance. On the other hand, if the 93 octane cars were tested on 93 , then they had the full advertised power-- power that would not be available in 91 octane States To the 93 octane cars.

With the M5 it would not be a slight difference in power/performance going from 93 to 91 octane. The increased boost in the F90 would not survive 91 and the computer would retard timing significantly to save itself. There was recently a 991.2 Turbo S versus the newest 992 GT3 and they were almost equal as the Turbo S was on 91 - that is a major performance hit. So - and I doubt it - IF the magazines have been using 91 instead of 93 - the F90 is going to run mid 10's at 132+ MPH lol.

[frankchn]

Originally Posted by vtknight

With the M5 it would not be a slight difference in power/performance going from 93 to 91 octane. The increased boost in the F90 would not survive 91 and the computer would retard timing significantly to save itself. There was recently a 991.2 Turbo S versus the newest 992 GT3 and they were almost equal as the Turbo S was on 91 - that is a major performance hit. So - and I doubt it - IF the magazines have been using 91 instead of 93 - the F90 is going to run mid 10's at 132+ MPH lol.

I think RON 95 / AKI 91 gas is acceptable at least on the F10 M5, according to the S63B44 technical training document. I haven't seen any evidence that this would change in the T4 revision of the engine.

[vtknight]

Originally Posted by frankchn

I think RON 95 / AKI 91 gas is acceptable at least on the F10 M5, according to the S63B44 technical training document. I haven't seen any evidence that this would change in the T4 revision of the engine.

Acceptable and optimal are two different things. The car will of course run - and the ECU is doing its job retarding timing to save itself from detonation. It is a fairly massive difference performance wise however.
These newer cars are not meant to be driven on lower octane values.

[frankchn]

Originally Posted by vtknight

Acceptable and optimal are two different things. The car will of course run - and the ECU is doing its job retarding timing to save itself from detonation. It is a fairly massive difference performance wise however.
These newer cars are not meant to be driven on lower octane values.

I can't find any recent sources, but according to a C&D test of 87 vs 91 done back in 2001, the E46 M3 with the S54B32 suffered a 6.6% drop in "track performance", but that is running with gas 4 points below the minimum requirement (I believe S54 has the same minimum 91 requirement as the current M5).

So I am guessing (without any real evidence) at worst horsepower will drop 5% or so perhaps? Not sure my butt dyno is accurate enough to measure that on the roads

[vtknight]

Originally Posted by frankchn

I can't find any recent sources, but according to a C&D test of 87 vs 91 done back in 2001, the E46 M3 with the S54B32 suffered a 6.6% drop in "track performance", but that is running with gas 4 points below the minimum requirement (I believe S54 has the same minimum 91 requirement as the current M5).

So I am guessing (without any real evidence) at worst horsepower will drop 5% or so perhaps? Not sure my butt dyno is accurate enough to measure that on the roads

This is the point I am trying to make. NA cars and FI cars are already a night and day in terms of how they are affected by octane (FI much more sensitive). But the latest FI cars are highly sensitive as they are tuned for more boost and timing to make the more powerful outputs we see today (and requisite performance). They are tuned for optimal performance on 93. The latest GTR's which added boost from the CBA 09-11 cars of 10.5 psi to 15 psi for the latest DBA cars is an excellent example as Motortrend tested the car many times in Cali and the results were so poor they started to add octane booster (to the Porsche's as well). For those trying to save some money on fuel - I suggest not buying these FI cars as you won't get the performance they are capable of. As to "evidence" - I would suggest asking any experienced Tuner who builds quick and fast cars. I have been racing for 30 years - and this is a very well known, basic concept. All of my cars tuned for street on 93 would ping if I got into boost on 91 - even with ECU adjustment. It's a big difference with the more powerful/higher boost FI cars. That said - if you are getting a new F90 M5 and don't think it's an issue - it is your car to test that theory with.