General topics » Fuel consumption on my European trip

A couple of observations regarding fuel consumption from my just ended European trip on the R1250RS.

My overall average fuel consumption to date including the trip is 61.8 mpg. (I have yet to reset since purchase).

When on mountain roads the bike appeared to sip petrol giving me a suggested range of circa 260 miles. That was typical of my readings down the B500 Schwartzwaldhochstrasse and when travelling the Julier and Maloja passes through to Switzerland and the Bernina and Albula passes coming back. A very pleasant surprise.

But when putting up with boring dual carriageways and higher speeds to get me places I struggled to get near those figures and my one burst at over 100 mph on German autobahn saw the fuel consumption figure falling faster than the speedo reading was rising!

There was some incredulity expressed on this forum at me taking a reserve can of fuel with me on this trip. I did not use it but it allowed me to get close to zero on the fuel gauge confident that I would not have to push a heavily laden bike for several miles. Courtesy of Covid-19 I had no previous experience of riding a fully laden R1250RS – panniers plus top box plus large Givi bag on the pillion seat plus my 15 stone.

On the trip out from Rotterdam to Karlsruhe I stopped at Bedburger Services on the A61 to refuel myself and the bike. That gave me circa 207 miles to my Karlsruhe hotel. I arrived with the TFT reporting 22 miles left in the tank and refuelled with 16.02 litres giving me a fuel consumption of 12.92 miles per litre. I was getting worried when the fuel reserve sign cut in being unsure of the distance to the hotel and PFS opposite and so slowed to circa 50 mph for maybe most of the last 30 miles (Lots of road works meant no hard shoulder meaning refuelling from my reserve might be very dangerous and I was trying to convert road signs in kilometres into miles as I rode on!!)

On the trip back I did the 230 miles from the Karlsruhe hotel to Jct 2 - Netettal - on the A61 near the German/Netherlands border arriving with the fuel gauge reporting 7 miles of fuel left. I was able to squeeze 17.15 litres into the tank indicating a fuel consumption of 13.411 miles per litre and that I would have had maybe 4 miles of fuel left when and if the gauge had hit zero. I aimed at a cruising speed of a true 75 mph on that trip with occasional burst of 85 when cheesed off by the boredom and some forced reductions to 80kph and 100kph forced by speed limits.

The difference between the two fuel consumptions on the A61 when the former should have been better than the latter is easily explained – I put 98 RON petrol in the tank knowing that I was pushing my luck. That gave me an extra 0.5 miles per litre (in fact marginally more because the journey down was at slower speeds for the last 30 miles or so i.e 9-10 miles of tank capacity)

Moral: If you are really pushing the tank capacity to the limit use 98 RON petrol. I don’t suggest that it is economic in terms of cost to do so but it may reduce your stress level. Without it I would likely have run out of fuel just before Jct 2 Netettal rather than arriving with about 10-11 miles of fuel left.

P.S. Now that I know my fuel range better I can leave the reserve can behind for most journeys safe in the knowledge that my fuel gauge is accurate and the art of the possible.

Chris

I must say that the 2 RS's i had did exactly the same on dear octane fuel as compared with the cheaper low octane.

I have been out with SWMBO who is a bit rusty on her bike after 2 yrs of not riding. Slow is not the word 🤔 Better slow than getting in a muddle though.
Anyway I did 222 miles before refilling and had 20 miles still reading on range..
God its hard work riding that slow. 😉

Octane doesn't change the heat energy content of the fuel. It only reflects the uniformity of the fuel ignition. The difference in mileage is what you would expect for E10 vs E0.

So its 17 and a bit litres until running dry - usefuel to know

Zitat von L2RKE im Beitrag #4

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I have been out with SWMBO who is a bit rusty on her bike after 2 yrs of not riding. Slow is not the word 🤔 Better slow than getting in a muddle though.
Anyway I did 222 miles before refilling and had 20 miles still reading on range..
God its hard work riding that slow. 😉

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At the moment I think she's forgotten how rapidly a bike can do an overtake.
It'll come back.

Zitat von wessie im Beitrag #3

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there are so many variables that I am sceptical about the thesis posited in the original post re. improved fuel consumption with posh petrol. You only need a slight tail or head wind to skew the figures. Then what about ambient temperature and pressure which affects O2 concentration. Tyre pressures the same? Are the gradients identical in both directions? Traffic density the same?

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Zitat von wessie im Beitrag #3

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there are so many variables that I am sceptical about the thesis posited in the original post re. improved fuel consumption with posh petrol. You only need a slight tail or head wind to skew the figures. Then what about ambient temperature and pressure which affects O2 concentration. Tyre pressures the same? Are the gradients identical in both directions? Traffic density the same?

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Zitat von L2RKE im Beitrag #4

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I have been out with SWMBO who is a bit rusty on her bike after 2 yrs of not riding. Slow is not the word 🤔 Better slow than getting in a muddle though.
Anyway I did 222 miles before refilling and had 20 miles still reading on range..
God its hard work riding that slow. 😉

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I added this to a different thread on this topic :-
I have tried that 'believe the fuel gauge' but never had the nerve to go beyond zero on either RS. Always find I must have more left in the tank as I always 'fill to the neck' knowing my ride home 6 miles with give me an air gap.
Doesn't seem to matter if I fill on mainstand, local use or sidestand touring a loaded bike. Never seem to get close to the supposed fuel tank capacity and not gone down the 'carry a 5litre can' test route.
Range obviously still dependant on speed and traffic but 200 miles and I would want a stop anyway.
This was from my last long range test and I still failed to get near empty - see ealier post from holiday 2017 - couldn't travel last year and now (hindsight 20/20) looks like this year will also be a miss.

My 'best' tank full to refill distance was probably from the BP garage 59760 Grande Synthe, 25 miles to the shuttle, then Dover 240 miles back to Shell services Kennford, outside of Exeter, Devon.
I had decided my last day home would be casual and also getting better mpg would avoid M25/M3 (Flete services) extorsion prices. I hoped to clear around 200 miles but kept going until the fuel light warning.
A reducing 50 miles range meant I could get nearly home, sat at 60/65 and I have just google mapped the distance in two stages, otherwise it made 300 miles with the tunnel addition.
My best estimate was 270 miles and each fuel refill was on sidestand, so back in Exeter area I added 17.18 litres ( my range was 10 miles to 'empty' on stopping)
270 miles/434 km equates as 71.45mpg
3.95 ltr / 100 km and 25.29 kpl

The last dealer service 2019 10,864 miles was the 12k service early for the planned trip to europe, replaced first set of tyres with Michelin road 5 despite having 1,000 miles range left. Reset the trip and this May, thanks to covid cancelled trips, home service was still short of 12,000 but the year total nav 5 mpg was 67.5 and since another reset may 2020 it is again at 67.5mpg
My 2005 R1200ST is just under 40,000 miles but that runs on shell super 98/99 octane I use on both ST and RS, averaging 55/60 mpg since ownership, 10,000 miles a set of tyres, still with original disks and pads (advised rear was worn, new pads 39,000 fitted but not needed?)
Boring for some, we are all different, but 4 trips to Norway from uk, R1200R,R1200RS (2015 model) and 2 trips 2017 RS were all comletely(ish?) within local speed limits (well below autobahn?)
It is just a case of the faster you go, faster you stop, the more 'non-average' your travel the less your average mpg will be!

P1000579.JPG - Bild entfernt (keine Rechte) I think this was 2018 holiday - 70 mpg lazey riding, nothing to do each day and all day to do it!
Better to have 8 hours @ 60mph than 6 hours @ 80 mph?

Zitat von Dave H im Beitrag #12

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Better to have 8 hours @ 60mph than 6 hours @ 80 mph?

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As a comparitor, during a 150 mile track day my R1250RS averaged 29.4 mpg. Safe to say that is probably the worst we should ever see.