M.P.G. ????

[Rockburner]

I always put Shell V Max in, when I have put a tank of supermarket cheap fuel in there is a drop in mpg of a couple of miles.

I've been running the Rockster on "high octane" for the last few tankfuls and its doing nearly 200 miles before reserve. Previously it would do about 160-175.

I'm probably riding more gently because I'm with a pillion 90% of the time now, but you'd think the extra weight would offset the gentler riding in terms of mpg.

[Scotsrich]

When my bike needs petrol I go to the petrol station and fill it up.

I’ve no idea of the mpg.

Am I doing this wrong?

[GuzziPaul]

When my bike needs petrol I go to the petrol station and fill it up.

I’ve no idea of the mpg.

Am I doing this wrong?

With the Le Mans its a way for me to measure the performance of an old bike and see the effects of maintenance. Especially when on a long ride. When I rode to Le Mans (race track) 3 years ago I was filling up every 100 miles as I was worried about running out of fuel, it was then I started recording the mpg, which was about 31mpg. With the changes I made ( but not to the right wrist) I got this up to around 41mpg by the end of last year.
Over the last three fill ups this year I'm around 38mpg so I reckon its time for a timing check and carb balance.

On the Tuono I just put fuel in, but reset the trip at every fill up I reckon i can do about 130 miles before the low fuel light comes on, again very handy for long european trips when you don't know where the next petrol stop might be. Especially usefull when doing 3-400 miles a day.

[Trinity765]

The Street Triple 765 is around 45mpg - no motorways or heavy traffic.

[Taipan]

I started off when I ran out of petrol after going onto reserve and had to push it for over a mile to the nearest petrol staion. Not having a trip I wanted an accurate measure of the milege and fuel going in and therefore work out any improvements from the changes I made. I have also diconnected the accelerator pumps, but it may be time to re connect them and do some more measurments, although acceleration on a 44 year old Le Mans is relative.

I always put Shell V Max in, when I have put a tank of supermarket cheap fuel in there is a drop in mpg of a couple of miles.

I do the same journey every day and my MPG always improves with the better Fuels, even Tesco momentum and certainly covers the extra cost.

[Supermofo]

I always put super in the 690 as it uses such small amounts and cos I pamper the bike like an old tart. Any old Super usually although Esso if I'm leaving it due to the no ethanol.

[tricol]

My Trident easily gets 60+ and I'd say that will get a bit better as the miles add on.

[Mr. Dazzle]

I always put super in the 690 as it uses such small amounts and cos I pamper the bike like an old tart.

My day to day bike (CBR600) and car (BMW 320d) both get Tesco own brand regular fuel, they don't seem to suffer for it.

I put Optimax in the Bonneville...but I'm in two minds as to whether it's worth it. On the one hand its an old engine design with fuelling that is less sophisticated than some lawnmowers (genuinely) and it's only 9:1 compression, on the other hand it was originally built to run on full fat high octane leaded fuel (4 star was 98RON, which is only matched by the 'name brand' petrols AFAIK). So I dunno what to do really!

[Rockburner]

I always put super in the 690 as it uses such small amounts and cos I pamper the bike like an old tart.

My day to day bike (CBR600) and car (BMW 320d) both get Tesco own brand regular fuel, they don't seem to suffer for it.

I put Optimax in the Bonneville...but I'm in two minds as to whether it's worth it. On the one hand its an old engine design with fuelling that is less sophisticated than some lawnmowers (genuinely) and it's only 9:1 compression, on the other hand it was originally built to run on full fat high octane leaded fuel (4 star was 98RON, which is only matched by the 'name brand' petrols AFAIK). So I dunno what to do really!

Somewhere near you (Haddenham I think) is a petrol station that sells non-ethanol, high octane stuff. I've not been there, so I don't know exactly what it is, but apparantly, it's what Dad used to run all his old bikes (especially the race bikes) on, and insisted was also used in the Aston (probably for the non-ethanol bit). Might be worth checking out?

[The Spin Doctor]

I get mid-50s out of the XJ6 and the Hornet 600. The XJ doesn't really change, the Hornet did drop to around 40 on one M4 / M5 ride that took me into a 50 mph headwind all the way. The old GSX-R750 with its stage 2 'tune' just ran ludicrously rich - it would do 40 mpg if I took it easy, high 20s on one high speed Autobahn trip to Austria. Filling up every 90 miles is tedious.

The 40-year old CB250RS gets about 70 mpg, though it doesn't get thrashed like the old despatch bikes. Interestingly, they used to return 80-85 fairly consistently... which tends to suggest that modern fuel doesn't go as far as it used.

[Mr. Dazzle]

I always put super in the 690 as it uses such small amounts and cos I pamper the bike like an old tart.

My day to day bike (CBR600) and car (BMW 320d) both get Tesco own brand regular fuel, they don't seem to suffer for it.

I put Optimax in the Bonneville...but I'm in two minds as to whether it's worth it. On the one hand its an old engine design with fuelling that is less sophisticated than some lawnmowers (genuinely) and it's only 9:1 compression, on the other hand it was originally built to run on full fat high octane leaded fuel (4 star was 98RON, which is only matched by the 'name brand' petrols AFAIK). So I dunno what to do really!

Somewhere near you (Haddenham I think) is a petrol station that sells non-ethanol, high octane stuff. I've not been there, so I don't know exactly what it is, but apparantly, it's what Dad used to run all his old bikes (especially the race bikes) on, and insisted was also used in the Aston (probably for the non-ethanol bit). Might be worth checking out?

I honestly don't even know if it's necessary! I use the name brand Optimax 'cause as far as I know it doesn't have ethanol. Pumps have to have the E5 logo anyway if the fuel does have ethanol, again AFIAK.

There's a forecourt inside Silverstone circuit which sells fancy petrol, I think they've got up to 105RON at some absurd price

[mangocrazy]

I also have my suspicions that MPG is noticeably less with modern petrol than with the older stuff. In the 90s I used to do a 90 mile round trip commute to work on the VFR 750 and I used to reliably get 45mpg out of it. I'd fill it to the brim (making sure the bike was on its centre stand) and with the 20 litre tank it would go onto reserve about 10 miles before I was due to fill up after two round trips (so approx 180 miles).

The last ime I did a long trip to test out MPG was when I rode it down to the gaff in France.I was struggling to get much over 130 miles out of a tank full. Part of this was due to me omitting to re-fit the centre stand, so I couldn't fill the tank right to the top, but even allowing for that MPG was noticeably worse on modern fuel with ethanol (E10 in France).

[Cousin Jack]

I am confused at all this worry about ethanol. Anyone remember Cleveland Discol? It was used in all sorts of cars and bikes, and I cannot recall any problems. In fact it was marketed as being a 'premium' fuel that made your engine run better.

From Pistonheads.
"In 1928, Cleveland Discol was introduced to the UK. Basically petrol blended with ethanol although the exact proportions are somewhat of a mystery. Probably around 10%, but figures of 20% can be found on the web. A retired oil company chemist I know, reckons the percentage was lower, perhaps around 5%."

[Rockburner]

I am confused at all this worry about ethanol. Anyone remember Cleveland Discol? It was used in all sorts of cars and bikes, and I cannot recall any problems. In fact it was marketed as being a 'premium' fuel that made your engine run better.

From Pistonheads.
"In 1928, Cleveland Discol was introduced to the UK. Basically petrol blended with ethanol although the exact proportions are somewhat of a mystery. Probably around 10%, but figures of 20% can be found on the web. A retired oil company chemist I know, reckons the percentage was lower, perhaps around 5%."

Ethanol (iirc) is known to have a respectably lower octane rating, so yes, it will affect power outputs the more of it is put into the fuel.

No idea about Cleveland Discol, but I remember my Dad talking about it.

[Mr. Dazzle]

I am confused at all this worry about ethanol. Anyone remember Cleveland Discol? It was used in all sorts of cars and bikes, and I cannot recall any problems. In fact it was marketed as being a 'premium' fuel that made your engine run better.

From Pistonheads.
"In 1928, Cleveland Discol was introduced to the UK. Basically petrol blended with ethanol although the exact proportions are somewhat of a mystery. Probably around 10%, but figures of 20% can be found on the web. A retired oil company chemist I know, reckons the percentage was lower, perhaps around 5%."

I basically DGAs about ethanol in my modern vehciles.

I only worry about it in the Bonnie cause it's got old seals and a tank which rusts better than a Lancia Beta. However my engine rebuild has featured modern seals and floats throughout and I'm gonna recoat the inside of the tank, so.....

[Cousin Jack]

Ethanol (iirc) is known to have a respectably lower octane rating, so yes, it will affect power outputs the more of it is put into the fuel.

No idea about Cleveland Discol, but I remember my Dad talking about it.

AFAIK ethanol actually INCREASES the octane rating, but it's energy density is lower, so produces less power.

[Dickyboy]

I am confused at all this worry about ethanol.

Ethanol seems to make plastic tanks expand, my Centauro ended up with stanchions hitting the tank on full lock, which theoretically is an MOT failure and its very difficult to refit a tank that's 10mm longer than it should be

[Rockburner]

Ethanol (iirc) is known to have a respectably lower octane rating, so yes, it will affect power outputs the more of it is put into the fuel.

No idea about Cleveland Discol, but I remember my Dad talking about it.

AFAIK ethanol actually INCREASES the octane rating, but it's energy density is lower, so produces less power.

Yes - that's it. (I knew my understanding of WHY it wasn't as good as petrol was off)

[mangocrazy]

I am confused at all this worry about ethanol.

Ethanol seems to make plastic tanks expand, my Centauro ended up with stanchions hitting the tank on full lock, which theoretically is an MOT failure and its very difficult to refit a tank that's 10mm longer than it should be

It's a known problem with many plastic fuel tanks. The tanks on Aprilia Falco?Mille/Tuono are well known for expanding to the point where it's damn near impossible to refit the tank. Ethanol also eats away at NBR seals, pipe and o-rings in the fuel line and makes metal fuel tanks rust internally due to phase separation and resultant water sloshing about.

So yes, on modern vehicles designed for it, it's not a problem. For older vehicles it most definitely is a problem.

I've replaced fuel lines on the VFR, Falco and 888 with Gates Barricade fuel hose imported from the USA, which conforms to SAE J30R14, and replaced all o-rings and seals with Viton equivalents. I'm also intending to get the VFR (metal) fuel tank de-rusted and internally coated when it returns from its tour of duty in France.

But even aside from all that, ethanol as fuel is shit. It means that vast tracts of land have to be set aside to grow the crops that are then (expensively) converted to fuel. So land that should be used for growing food for the world is instead used to grow crops for ethanol. Can someone tell me how that is supposed to be 'green'? It's also a lovely little earner for already filthy rich landowners, raking in subsidies. The whole thing stinks, but rich people are getting richer so it ain't gonna stop any time soon.

[Mr. Dazzle]

Ethanol (iirc) is known to have a respectably lower octane rating, so yes, it will affect power outputs the more of it is put into the fuel.

No idea about Cleveland Discol, but I remember my Dad talking about it.

AFAIK ethanol actually INCREASES the octane rating, but it's energy density is lower, so produces less power.

Yeah, supermarket own brand performance stuff tends to increase the RON by adding ethanol, Shell and Gulf stuff does it the old fashioned way. Not sure about BP.