[MTHX]

Originally Posted by vtknight

This is the point I am trying to make. NA cars and FI cars are already night and day in terms of how theY are affected by octane. But the latest FI cars are highly sensitive as they are tuned for more boost and timing to make the power outputs we see today (and requisite performance). They are tuned for optimal performance on 93. The GTR 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 money on fuel - I suggest not being 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.

the problem is not the money, it’s more the ability to put some good 93 octane fuel on the car.

there, (in canada) we have petro canada that has a 94 octace, but with 15% ethanol mixture ...

if i compare from shell, they have a better 91 octane fuel than petro-canada 91. (probably the quality of aditive)

bmw need to provide some certified octane booster lol

[frankchn]

Originally Posted by vtknight

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.

If an engine is rated for a certain performance with 93 octane gas, then running a 91 octane fuel through the system will be detrimental to performance.

Tuned engines do run boost at much higher than most manufacturers, so naturally they would be more susceptible to fuel quality issues. The engine themselves might not be able to retard timings enough to compensate for poorer octane ratings if they are running with extra boost.

That said, I think if BMW specifies that the minimum requirement to run the S63 engine is 91 octane, then using 91 octane gas is fine, even if the engine is not performing at the same rated horsepower as when using 93 octane gas.

I've not heard of any issues with knocking due to people putting in 91 gas rather than 93 gas in stock S63 engines, and I think that holds true for the new revision of the engine in the F90 M5 as well. Of course, if you tune, everything goes out the window.

[frankchn]

Originally Posted by MTHX

bmw need to provide some certified octane booster lol

There is a gas station selling 100 octane near my place, so I plan to mix 91 and 100 to get 93 if I am going to push the car etc....

[vtknight]

Originally Posted by frankchn

If an engine is rated for a certain performance with 93 octane gas, then running a 91 octane fuel through the system will be detrimental to performance.

Tuned engines do run boost at much higher than most manufacturers, so naturally they would be more susceptible to fuel quality issues. The engine themselves might not be able to retard timings enough to compensate for poorer octane ratings if they are running with extra boost.

That said, I think if BMW specifies that the minimum requirement to run the S63 engine is 91 octane, then using 91 octane gas is fine, even if the engine is not performing at the same rated horsepower as when using 93 octane gas.

I've not heard of any issues with knocking due to people putting in 91 gas rather than 93 gas in stock S63 engines, and I think that holds true for the new revision of the engine in the F90 M5 as well. Of course, if you tune, everything goes out the window.

I think your mind is made up - which is fine. I did not say the car will knock on 91. I am saying the performance will be significantly degraded. For example - you will not go 10.9 at 129 MPH on 91 octane. Maybe an 11.4 or 11.5 at 122-123 MPH. If that isn't an issue for you - then all is well.

[frankchn]

Originally Posted by vtknight

I think your mind is made up - which is fine. I did not say the car will knock on 91. I am saying the performance will be significantly degraded. For example - you will not go 10.9 at 129 MPH on 91 octane. Maybe an 11.4 or 11.5 at 122-123 MPH. If that isn't an issue for you - then all is well.

Definitely, I do expect a degradation in performance when running on pure 91.

(I don't expect the engine to break though )

[vtknight]

Originally Posted by MTHX

the problem is not the money, it’s more the ability to put some good 93 octane fuel on the car.

there, (in canada) we have petro canada that has a 94 octace, but with 15% ethanol mixture ...

if i compare from shell, they have a better 91 octane fuel than petro-canada 91. (probably the quality of aditive)

bmw need to provide some certified octane booster lol

I'm in Toronto - so I understand. Two things from my point of view: ethanol is not a bad thing, at all. That said - with any additive - consistency will be an issue versus raw octane. Ethanol is literally used in almost every bigger power race application today. The car I use for drags is on E98. E98 allows me to push the tune on my car past what C16 or Q16 allows (although C16 and Q16 are both higher octane fuels). Ethanols "trick" is it both cools the engine, but requires a ton more fuel (about 40+% depending on the tune and car). By providing more fuel to burn and keeping the temps down - timing and boost can be increased. It is not a street fuel - despite being available in the US quite plentifully (at least at the E85 and lesser levels - though some do have "E100") - again - due to very poor mileage. I consume almost 3 gallons of fuel in one 1/4 mile pass (due to 3300 CC's of injector).

So for pump fuel tunes - 94 octane is where it is at - although I have found some Esso 93's to work well with my other cars. Jury is still out as they have some serious negative press.

My M5 will only be on 93 or greater octane as I want the performance I purchased - all the time.

[frankchn]

Originally Posted by vtknight

My M5 will only be on 93 or greater octane as I want the performance I purchased - all the time.

I would totally get 93 if only it were actually available in California

[vtknight]

Originally Posted by frankchn

I would totally get 93 if only it were actually available in California

And I get that - and that does suck. The magazine test where they had to add octane booster was in Cali. All you can do is what you stated above - mix with 100 and pray for a higher overall number. If you have enough - you could get almost 96 lol.

[Stealth7]

So if the M5 has to run 91 in CA with degraded performance and the E63s is designed for 91 and has full performance ... . The real question is what octane fuel was in the M5 for the test?

[vtknight]

Originally Posted by Stealth7

So if the M5 has to run 91 in CA with degraded performance and the E63s is designed for 91 and has full performance ... . The real question is what octane fuel was in the M5 for the test?

I personally cannot believe the E63S was designed for 91. That said - I will read the article and see if it is mentioned.

EDIT: Fuel used was not mentioned. The test was in Cali.

[KevinM]

Impressive showing, especially since C&D hasn't been kind to BMW or M lately. Back to the future then - circa 2000!

[M3 Adjuster]

Originally Posted by esquire

Good result. But I don't understand how they give the m5 and the e63s the same marks in the quarter mile , when the m5 has been measured with a faster quarter mile. Someone explain that to me.

the M5 has a faster quarter mile as measured by WHOM? Car and Driver does their OWN tests and measurements.

https://www.caranddriver.com/feature...-c-d-test-cars

[M3 Adjuster]

Originally Posted by 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?

out to pasture...

[Richy Rich]

I'd still take the new Panamera over all of them.

[Teutonic]

Logical, the M5 is the best choice in here anyway.
And of course it's a winner. Any doubts?

[AudiA4]

Originally Posted by shahin

The biggest joke is they gave more points to Cadilack over Porsche
Not Bias at all

The CTS dominated in chassis development and the fun to drive category, and for $75,000 LESS than the Porsche (the cost of an additional M3!)...so why do you find this surprising?

[vtknight]

Originally Posted by M3 Adjuster

the M5 has a faster quarter mile as measured by WHOM? Car and Driver does their OWN tests and measurements.

https://www.caranddriver.com/feature...-c-d-test-cars

I like the fact CD uses Race Logic boxes - I'm not sure if all the other Mag's do (or what equipment they use) - but it is sophisticated enough to give fairly reliable results. As Road and Track ran the exact same 0-60 and 1/4 ET, but with a 127 MPH trap - it is showing the results are consistent over different testing days, tracks and drivers.

Either way you slice it - this F90 M5 is quicker and faster than any stock R35 GTR from the factory - including the NISMO. It also ties the GM provided C7 Z06 0-60 and 1/4 mile times. That is a crazy fact for a four door, 16 foot, 4300+ lb luxury GT car.

[raysspl]

Always glad to see BMWs taking 1st place

[Brake_Late]

Originally Posted by DallasLife345M

Winning

[Brake_Late]

I know I couldn't take my eyes of this one yesterday... even standing still !

[IANNUZZI]

Originally Posted by vtknight

I like the fact CD uses Race Logic boxes - I'm not sure if all the other Mag's do (or what equipment they use) - but it is sophisticated enough to give fairly reliable results. As Road and Track ran the exact same 0-60 and 1/4 ET, but with a 127 MPH trap - it is showing the results are consistent over different testing days, tracks and drivers.

Either way you slice it - this F90 M5 is quicker and faster than any stock R35 GTR from the factory - including the NISMO. It also ties the GM provided C7 Z06 0-60 and 1/4 mile times. That is a crazy fact for a four door, 16 foot, 4300+ lb luxury GT car.

No, the F90 M5 is limited to 163mph so it is not faster than any stock GTR which achieves 190+

No, the F90 M5 is not quicker than any stock GTR 0-60mph, a stock GTR can go as low as 2.7. They can also go as low as 2.6 on 335s

2012 Nissan GT-R Premium 530 448 2.9 11.2 122.7 101 1.05 23.3 sec @ 0.89 g
2013 Nissan GT-R Black Edition 545 463 2.8 11.1 124.8 105 1.03 23.0 sec @ 0.91 g
2014 Nissan GT-R Track Edition 545 463 2.7 11 125.1 94 1.04 23.0 sec @ 0.93 g
2015 Nissan GT-R NISMO 600 481 2.9 11 126.6 97 1.06 22.9 sec @ 0.91 g
2016 Nissan GT-R 45th Anniversary 545 463 2.9 11.2 122.0 103 1.0 23.5 sec @ 0.90 g

[DS_BMW]

0-100 in 6.6!