and was shocked by the results, especially for the impreza, jeepers over 10% more torque and 14hp just from a fuel change. Perhaps my "seat of the pants o meter" is more sensitive than I thought
The K, like many, will run on 95 but BMW recommend >98 for optimum performance. Are the R12S's the same? I don't imagine it makes any difference on the old R11S motors? I've not noticed so anyway.
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Steve Parry
Current fleet: '14 F800GS, '87 R80RS, '03 R1100S BoxerCup, '15 R1200RT LE Dynamic, '90 K1, '05 K1200S
My 12S ran much better (smoother and a little quicker to rev up) on super unleaded. It too was designed to run on super, like the K, but would accept standard 95 RON fuels.
I think in a normal bike it may be less noticeable, but BMWs change their ignition timing slightly on 95 RON fuels, and only run at "full performance" on super. that’s how I understand it anyway....
It makes a huge difference on my 12S, if I have to use 95 ron ( as usual in wales) I get a much harsher engine vibe and poor performance along with much reduced mpg, on 97/98 or tesco 99 it runs very sweet and my mpg is improved by around 30 miles per tankful.
Steve
Well-weathered leather
Hot metal and oil
The scented country air
Sunlight on chrome
The blur of the landscape
Every nerve aware
My 12S ran much better (smoother and a little quicker to rev up) on super unleaded. It too was designed to run on super, like the K, but would accept standard 95 RON fuels.
I think in a normal bike it may be less noticeable, but BMWs change their ignition timing slightly on 95 RON fuels, and only run at "full performance" on super. that’s how I understand it anyway....
yes that's my understanding.
Really shocked with the additional hp and torque 5th gear got in their test
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Steve Parry
Current fleet: '14 F800GS, '87 R80RS, '03 R1100S BoxerCup, '15 R1200RT LE Dynamic, '90 K1, '05 K1200S
I think an engine needs to have a knock sensor in order to take advantage of high octane.
Otherwise it’s a waste of money.
The 1100 doesn’t have it, but the 1200 does. Don’t know about the 1150.
Tapio wrote:I think an engine needs to have a knock sensor in order to take advantage of high octane.
Otherwise it’s a waste of money.
The 1100 doesn’t have it, but the 1200 does. Don’t know about the 1150.
//T
I'm not 100% sure, but I would have thought it would have been the opposite. If an engine isn't tuned to take advantage of the higher octane fuel, using it will be of no benefit. With a knock sensor fitted the EMU can back off the ignition advance to prevent pre-ignition when lower octane fuel is used.
My 11S made no difference with higher octane stuff.
I've been advised by the previous owner of the K100 I've just bought to use the higher octane stuff in that as there is less ethanol than normal petrol and the ethanol knackers all the seals.
The 1200 is designed / tuned to use 98 RON, at least if you want optimum performance. It has a knock sensor to retard the ignition when using low octane fuel.
Personally, I can't feel any difference so typically use 95. On occasion I bung a tank of the good stuff in expecting to feel some change, but never do.
My 11s does approx. 20 more miles per tank on '98. Can only get it across the border though..
_________________
Nigel
Keep smiling, it makes people wonder what you've been up to!
1999 R1100s (mandarin) '
2018 DL 250V Strom
2019 CB125F Honda.
MZ301 Saxon Fun ( currently retired)
'03 Bullet 65 project..
SAS Tom wrote:My 11S made no difference with higher octane stuff.
I've been advised by the previous owner of the K100 I've just bought to use the higher octane stuff in that as there is less ethanol than normal petrol and the ethanol knackers all the seals.
depending on the age of the K100 you may need leaded, I seem to recall that most of the 8 valves didn't have the hardened valve seats required, oddly enough the airheads from the era did so I'm puzzled why BMW didn't equip the K's thus?
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Steve Parry
Current fleet: '14 F800GS, '87 R80RS, '03 R1100S BoxerCup, '15 R1200RT LE Dynamic, '90 K1, '05 K1200S
I was wondering about this, so tried a tank of 98, and had worse mpg.... I think I'll try it again though and try to compare with similar riding conditions, after this discussion...
I filled up my GS a few weeks ago, in France - on 98RON, and the consumption improved approx 8%.
In some situations (where you are putting a lot of miles in a day) it can make the difference between filling up once, or filling up twice - that can make a significant difference if you are on a schedule.
The engine seemed to pick-up easier too.
Al
If I am ever on life support - Unplug me......
Then plug me back in..........