Ordinary unleaded or Super?

[IainMac]

in theory you should use the lowest octane fuel that allows the optimum ignition advance for you engine, as the faster burn of lower octance should give the better power, whether or not thats 95 or 97+ depends on the engine/operating conditions.
The GS could be looked upon as a low hp design (compared to japs etc) and not require higher octanes but as the pistons are large /air cooled its also more likely to suffer pre ignition. I would suspect that in hotter climes the use of 97 may be of benifit if you going to rag it, elsewhere 95 should do (if specced in the manual?) . That said fuel has a marked effect on economy, my old GS1150 jumped from struggling to break 40mpg to 50+ when I took it to spain (same rider same technique, same fuel rating), it returned to normal on my return...
And my now gone TVR runs better (crisper, perkier) on 95 (under normal ops) than 97? under hot conditions that would probably be reversed.

 

[North]

I use the highest grade the station has.

It just seems like the common sense thing to do, to get the most out of the bike. And I like to do my part to support BIG Business.


North

 

[ELIMINATOR]

Warthog appears to be the only one Actually doing anything about testing this out

Look forward to seeing the results.Even then it would be unlikely to be the definitive answer, as unless he / she? plans to do it on a test track with the same atmospheric conditions over several tankfuls.

I'm sure Warthog would agree, but it is still better than nothing.

You pays your money, you takes your choice.

 

[Tarka]

Wherever I see Shell 98 Octane Superplus,I fill my 1100`s with that,as they definately run better on it....you can FEEL the difference.
In Italy,I discovered 100 Octane pump petrol

The Airhead gets anything going,as it would probably run on paint thinners in an emergency

 

[wessie]

In Italy,I discovered 100 Octane pump petrol

100 RON fuel was widely available in Germany, Austria & Italy this summer.

Oddly, amongst others, it was being sold by ARAL which is a subsidiary of BP. The UK website says that BP Ultimate "has a minimum 97 RON".

 

[Warthog]

Warthog appears to be the only one Actually doing anything about testing this out

Look forward to seeing the results.Even then it would be unlikely to be the definitive answer, as unless he / she? plans to do it on a test track with the same atmospheric conditions over several tankfuls.

I'm sure Warthog would agree, but it is still better than nothing.

You pays your money, you takes your choice.

I'm only "she" on very special occasions, thank you very much, and as much as I enjoy this forum, this ain't one of them occasions!! Still, if you could see what I was wearing, you'd be forgiven for the mistake!!

I will do a comparison: I hope to do maybe two tankfuls on the optimax to see what happens. BUT....don't expect the results any time soon as I'm the one always moaning and whinging about a slipped disc so my weekly mileage, is about 30 miles instead of the normal 250-300! Still, as I do a bit of motorway and town on my trips to the osteopath, I should get a variety of engine behaviour, and as its the same trip, it should be comparable from one tank to the next albeit over a range of athmospheric conditions. (NB, if the forum wants to pay for a track day for me, I'll willingly bear the pain, all in the name of science, of course ).
My plan is to fill up when I next get an empty tank and use Optimax. I'll make a note of how much I filled up with, and how much I spent. The volume filled will allow me to do a check on how much the equivalent in 95RON would have cost and therefore calculate a £s-of-petrol-per-mile score and an MPG score. Then I'll fill up with optimax and run it for say 200 miles, fill up noting cost and volume for another cost/mile and MPG score and once more fill with Optimax and repeat a second time. The results will dictate if the third fill up is also Optimax or back to regular! .

If my methodolgy seems flawed in some way, please say, but as simple experiments go, I think it should be OK. If economy does warrant the use of Optimax, we could be looking at a power increase for effectively no extra cost!

 

[Bigtwin]

I tried running my 1150 on a couple of tanks of Super-dooper expensive bell and whistles fuel (so that's about 500 miles, more or less) as opposed to the usual regular. If it did make any difference, a) I couldn't feel it when riding, and b) it didn't make enough difference to the fuel consumption to be able to tell on tank range type analysis. It was "reassuringly expensive" though,

 

[GSmonkey]

I seem to remember we've had this debate a few times. My thoughts are that you should run on both back to back and see what you think. IMHO on the 12GS it certainly seems to run smoother and the engine picks up better on the 98RON. That said, it only gets fed on 98RON when I'm going to be enjoying myself down some nice country lanes - any other type of riding and it gets the cheap stuff.

 

[Tim Cullis]

BMW says NOTHING in its 1200GS documentation about using higher than 95 octane. Surely if you could get better performance or better fuel economy by using 98 octane BMW would have claimed it.

Tim

 

[Llama]

As others have said I get about 15 miles more per tank and the bike feels better. Smoother and with a bit more oomph (technical term). When I use the higher octane fuel. I try and use it where I can.

Ralph

 

[Deadskin]

Air temp

The bike was flying today in the cool damp air,
would've taken off if i didn't have half of salisbury plain stuck to it

 

[JDH]

I can't be alone in finding the fact they post about life the universe and everything and seldom nothing to do with their coveted 1200's but insist on saying it in the cosy comfort of their own forum can I?

Recent quote Judge, make yer mind up fella :slideface

JDH

 

[ELIMINATOR]

Warthog, I'd make sure the tank is as empty as possible, not having just flashed up the fuel light, as the "old" fuel will dilute the super dooper fuel.

Hmm, there's an ABBA song there somewhere.

Just thinking about Ag (bugger can't spell it) the blonde one's bum each:

 

[roly]

fuel

any pump with no one at will do, should have a seperate till for card holders only.cash payers inside . card though window.

 

[gasman]

I use 98 or super or whatever rather than plain old 95, cos it stops my 1150 from popping/detonating in the exhaust, and I guess that can only be good..

ps I took my catalytic converter out.

 

[steveuk]

always shell optimax

I suppose you 12 gays, sorry guys can afford super unleaded. .................There again, I suppose the mileage that you do it doesn't matter.

50k a year, '05 1200GS always use shell optimax, better mpg (slightly) and smoother engine.
mate also swears by it for his 92 GS and '95RT

 

[(RIP) Kaister]

they concluded that engines that have an active knock control benefit more as the engine adjusts to the better quality fuel

my 1988 saab 900 turbo has active knock control - and responds much better with more octane in the fuel.

my 1100GS ? - can't tell the difference

 

[Warthog]

What is active knock control? Sounds like an unpleasant contraceptive....

 

[matt_bailey]

My old Varadero - big V-twin, used to run much more smoothly on Shell Optimax, which I found especially beneficial in traffic where slow control was much easier.

I initially tried Optimax because you feel when a cylinder 'misses' on a twin more than on four cylinder engines. So, I thought the GS would benefit from the fuel too, but I've found that on my 1150 there is little if any detectable change.

 

[cookie]

What is active knock control? Sounds like an unpleasant contraceptive....

a sensor on the head detects detonation (knock or pinking) & via the ECU advances the timing to just below the critical point to take advantage of higher octane fuel.

high octane is just a reference to the fuels abilty to delay detonation. high octane fuel cannot produce more power unless the engine can take advantage by altering the timing.

the 1100 & 1150GSs do not have knock sensors.