[JIGGAM5]

So last week I went to Sunoco to put some racing fuel in the beast 70% 260 GT and 30% regular 93. The M5 performs amazing with racing fuel.:biggrinbounce: Touch the gas and hold on. So after a week of cruising on $7.43 a gallon for the special OPEC juice I went and put 93 in from Shell.
What the heck did I do that for. The car felt like it had allergies. Sluggish and the tach bouncing all over the place.:M5rev: It must have taken a good 1/4 tank before the car settled down. I see that on the board alot of people say they use Shell because of course its TOPTIER but I have had to many misfires and unstable idling when I put it in. I think i I am going to stick to Chevron which is also TOPTIER . Not trusting what coming out of these Shell gas stations lately. My opinon and thoughts.

Here are the specs on the racing fuels available out there: Racing Fuels

 

[IndyRedBeast]

So last week I went to Sunoco to put some racing fuel in the beast 70% 260 GT and 30% regular 93. The M5 performs amazing with racing fuel.:biggrinbounce: Touch the gas and hold on. So after a week of cruising on $7.43 a gallon for the special OPEC juice I went and put 93 in from Shell.
What the heck did I do that for. The car felt like it had allergies. Sluggish and the tach bouncing all over the place.:M5rev: It must have taken a good 1/4 tank before the car settled down. I see that on the board alot of people say they use Shell because of course its TOPTIER but I have had to many misfires and unstable idling when I put it in. I think i I am going to stick to Chevron which is also TOPTIER . Not trusting what coming out of these Shell gas stations lately. My opinon and thoughts.

Here are the specs on the racing fuels available out there: Racing Fuels

Just a question for you. I've been using 91 octan fuel since i bought my beast. Bought would 94 octane boost the car more?

 

[WallyM5]

Yes, but it will take a little while for the engine management system to recognize it and adjust accordingly. In Europe they have 93-98 octane. Going from 91 to 94 should result in a few extra HP but I doubt you would feel the difference. On a dyno you could see the difference.

 

[brutus]

Just a question for you. I've been using 91 octan fuel since i bought my beast. Bought would 94 octane boost the car more?

From the manual: "Required fuel

Super Premium Gasoline/AKI 93
Always use this premium grade fuel to obtain
maximum fuel economy and performance.
The minimum approved fuel grade is AKI 91.

Do not use gasoline below the specified
minimum quality, as otherwise engine
damage can result."

My '06 M5 using 91 (max available here in CA and many other states in the US) almost always has pinging under moderate to wide open throttle and occasional erratic idle, when I run Torco 94 the car runs much smoother, better performance? Feels like it but don't have any numbers.

Cheers,
Brutus

 

[M6Cabrio]

Adding race fuel isn't going to do anything for you at ALL except help you mentally. It has been proven on our beasts it does not give you a HP increase unless you have mods. You are just wasting your money at $8 a gallon.

Also the European rating is different than the US, so that 98 you see in Europe is like our 91 here.

 

[ZINC]

racing fuel did nothing for me, if it did anything it felt slower and underpowered....

 

[brutus]

Correction Euro 98 == US 93 - 94 (it's roughly Euro (RON) == US (AKI) + (4 .. 5)

 

[ZINC]

Seriously my car is still sluggish even after evening out the octane mix......

 

[brutus]

Back to the OP's issue of the car running poorly after returning to 93 ... Yup, I have the same issues, it appears the engine management computer takes awhile to adjust to the lower octane, in my case 1/8th a tank or so, likewise it takes awhile to adapt to the higher octane and realize the full benefits.

The OP was running 70% 100 and 30% 93 or ~~ 98 octane, at the gas station I use they have Torco racing gas at the pump in 87, 94, 96, 98, and 100, compared to the standard CA 91 octane I feel the most difference going from 91 to 94, can't say I've really felt any additional difference using 96, 98, or 100.

A problem with all of us comparing our experiences with racing vs premium gas is that some states like CA premium is 91 while other states it's 93-94 and even the BMW manual states 93 is required and 91 is the absolute minimum, adding to that I've read several times in recent years (last time, last year) that there are up to 20 different regional formulas for gas based on the state your in :crying: making very difficult to compare from one state to another.

Cheers,
Brutus

 

[JIGGAM5]

If anybody thinks that AKI doesnt do anything for the vehicle. Cmon . First of all if your AKI is low and your cars knock sensor hears detonation and it retards the timing this results in a loss of power output. It is proven and has been proven. More octane, ECU see this and advances your timing resulting in more power output. Not only that but you think these carmakers get this dirty gas thats in some stations.
When you get 91 you are only blending the high with the low. 88,89 with 93,94 which gives you 91. Its the same as synthetic oil with coventional oil. Product Synthetic blend. Im not saying the car has 510 hp now but with the higher octane your compression of 12:1 will be achieved without detonation. The car wants controlled burning

 

[M6Cabrio]

If anybody thinks that AKI doesnt do anything for the vehicle. Cmon . First of all if your AKI is low and your cars knock sensor hears detonation and it retards the timing this results in a loss of power output. It is proven and has been proven. More octane, ECU see this and advances your timing resulting in more power output. Not only that but you think these carmakers get this dirty gas thats in some stations.
When you get 91 you are only blending the high with the low. 88,89 with 93,94 which gives you 91. Its the same as synthetic oil with coventional oil. Product Synthetic blend. Im not saying the car has 510 hp now but with the higher octane your compression of 12:1 will be achieved without detonation. The car wants controlled burning

And you think our cars have KR (knock retardation) on 93 octane? I know mine doesn't....and if yours does I think something is wrong lol

Now if you mod the car, that is a different story.

 

[JIGGAM5]

If you think your engine doesnt have a knock sensor. Lmao It probably doesnt have a camshaft senor,crankshaft and a mass airflow sensor either,just to name the very few important components.
The M5 engine is engineer to the highest specs. You cannot achieve this while throwing a cyl. and a block and fuel together. I know you think the ECU is for added weight because your backside is too heavy. Of course But hey I will even give you the code for the knock sensor
when it breaks in your V10. 0F for table K6 or how about the code for the 5 other knock sensors in the engine. Or check the 3 internal knock modules.....

 

[Revo]

Running higher octane fuel isn't going to boost power, per se.

What it does do is reduce the likelihood of detonation and therefore the engine will not pull as much timing and you'll end up having more power than you would with lower octane fuel. But it's not going to boost power like nitrous or something...

 

[///M-five]

An interesting episode of Fifth Gear that deals with this subject ;
YouTube - 5th Gear - High Octane Fuels

 

[Vodyk]

interesting stuff!

 

[M6Cabrio]

If you think your engine doesnt have a knock sensor. Lmao It probably doesnt have a camshaft senor,crankshaft and a mass airflow sensor either,just to name the very few important components.
The M5 engine is engineer to the highest specs. You cannot achieve this while throwing a cyl. and a block and fuel together. I know you think the ECU is for added weight because your backside is too heavy. Of course But hey I will even give you the code for the knock sensor
when it breaks in your V10. 0F for table K6 or how about the code for the 5 other knock sensors in the engine. Or check the 3 internal knock modules.....

HUH? English is the best language here lol

And are you implying that I think our cars don't have a knock sensor? If so I said we don't have KR on 93 octane....I assumed you knew what that meant.





.

 

[Revo]

HUH? English is the best language here lol

And are you implying that I think our cars don't have a knock sensor? If so I said we don't have KR on 93 octane....I assumed you knew what that meant.





.

I think he was using maximum sarcasm to say that if the S85 doesn't have a knock sensor then it also doesn't have [laundry list of vital engine sensors], meaning he very much thinks our cars have plenty of knock sensors.

 

[JIGGAM5]

An interesting episode of Fifth Gear that deals with this subject ;
YouTube - 5th Gear - High Octane Fuels

Excellent Video by fifth gear. Alot of people need to get educated in this matter.

 

[Ahmed]

For people like us, race fuel is the only option for added performance lost in the first place. Because we only have 91 Octane pump gas with sulfur content ( which is a b**tch for DFI cars )

 

[brutus]

Excellent Video by fifth gear. Alot of people need to get educated in this matter.

Right, so the 3rd car (Impreza) had the highest performance engine, they tested Regular 95 (RON == 91 AKI), BP Ultimate 97 (92-93 AKI), and Shell Optimax 98 (93-94 AKI). From Regular to Optimax they got a 6% increase in HP and 11% increase in torque. Would be interesting to try the same experiment on the E60 with CA Regular 91 vs say Torco 94, maybe some day I'll get the time ... comments?

Cheers,
Brutus