RFL

[slparry]

riding my K at legal speeds resulted in 68.7 mph on the motor up and from Scotland, mixed speed riding while in the Highlands brought that average down to 58.8 mpg so, given it's a 157 hp machine I think that compares favourably with economical cars.

My F650 does 55 mpg, I believe the injection versions are closer to 80 mpg. Andy (with the F800) who's been on several trix weekends reckoned his F800 was 70 plus mpg without trying.

The Japanese seemed to have lost the plot a bit with mpg figures though, my ZX12R was very similar performance to my K12GT yet struggled to better 35 to 40 mpg

If I wind the K harder sure I can get it down, but mid 40's is the lowest I've managed

[bikesnbones]

I guess I had always imagined up until that point that a 1 litre bike would have as good as, if not better fuel economy than a 1 litre car - due to weighing a lot less

Totally agree.
I had this argment recently with someone who fiercly defended the lousy consumption we have to accept.


Point 1) Yeah but bikes rev a lot higher than cars
OK but not in all cases, and certainly not in the case of low revving cruisers...

Then we got onto the ridiculous cost of buying a big bike.

Point 2) They have supercar performance
Yeah but, tack a wheel on either end of a 100bhp engine and of course it's going to be ballistic.
It's not some miracle of modern engineering that we should be charged through the nose for.
It's just physics / power to weight ratio.
I don't think anything will change based on my experience that riders actually defend the appauling value for money we put up with.

And don't get me started on build / finish quality.

[Twinspark]

Tune a car engine to 100bhp / litre and see what that does to economy.

Then try taking it to 180bhp / litre, as we get from a modern supersport bike.

If you put a 180bhp 1litre engine in a car, the economy would be awful.

(there are some really shocking figures coming back on the Ford 1litre 'ecoboost' with 125bhp - with many owners reporting 35mpg averages)

[bikesnbones]

(there are some really shocking figures coming back on the Ford 1litre 'ecoboost' with 125bhp - with many owners reporting 35mpg averages)

Wow.
That's the same as my 13 year old Rover 1.4

So much for progress.
I've heard similar feedback regarding the Toyota iQ
Allegedly, the last word in small car efficiency.
2 Journalists took two of them on a long "economy" run, and both came in about the same, at just under 35mpg.

[McBoxer]

Just to change tack slightly, I read earlier (on parliament.uk) that "the tax disc was introduced in 1920, and the tax charged at a graduated rate of £1 per horsepower".
Interesting. I wonder how that would go down today?
http://www.publications.parliament.uk/p ... /90705.htm

[conkerman]

All of these little turbo wonder engines are awful in the real world.

Ecoboost engine and others are designed to skirt around the NEDC test for certification.

Its pretty much the be all and end all for manufacturers at the moment.

To be fair Steve, the BMW K motor was pretty groundbreaking, with its very aggressive fuelling strategies and active knock protection.

The ZX-12R is pretty much a decade older and uses the time honoured Japanese technique of when in doubt, go rich.

Any of the ninjas done't really encourage sedate riding though do they

[McBoxer]

All of these little turbo wonder engines are awful in the real world.

I've heard similar horror stories about the Fiat "Twin Air" engine. Not sure how true they are?

To be fair Steve, the BMW K motor was pretty groundbreaking, with its very aggressive fuelling strategies and active knock protection.

Fairly common in the car world though, due to emissions regulations. How long until bikes are forced to follow?

Any of the ninjas done't really encourage sedate riding though do they

Amen!

[slparry]

Tune a car engine to 100bhp / litre and see what that does to economy.

Then try taking it to 180bhp / litre, as we get from a modern supersport bike.

If you put a 180bhp 1litre engine in a car, the economy would be awful.

(there are some really shocking figures coming back on the Ford 1litre 'ecoboost' with 125bhp - with many owners reporting 35mpg averages)

yebbut .... on the other hand a bike's not dragging a ton of metal around every time you press the throttle is it

Whichever way you look at it the Japanese have got lazy over the last few years, on the bike side that is, Japanese cars are fuel efficient, but their bikes are not so.

That laziness was what allowed BMW to get the jump on them with the S1000RR and effectively give them two fingers right in the heart of their core market. The same is happening with fuel economy, the Japanese are still going down the old route of elevated red lines and powerbands while forgetting that consumers are now looking at economy as well.

The K12/13 and F800 series of engines prove that you can have useable performance and economy. I also recall several here saying the R12's are also miles better than their predecessors on MPG.

It's lazy design and marketing to think we can have either mpg or mph. With modern electronics we can have an acceptable mix of both.

[slparry]

All of these little turbo wonder engines are awful in the real world.

Ecoboost engine and others are designed to skirt around the NEDC test for certification.

Its pretty much the be all and end all for manufacturers at the moment.

To be fair Steve, the BMW K motor was pretty groundbreaking, with its very aggressive fuelling strategies and active knock protection.

The ZX-12R is pretty much a decade older and uses the time honoured Japanese technique of when in doubt, go rich.

Any of the ninjas done't really encourage sedate riding though do they

Well ....... the KGT's competitor the GTR14 has less power and a modern engine but it is typically 10mpg below what the K12 makes.

MCN list the K12GT as 47 mpg, and the GTR as 36 mpg.

the FJR is also less HP but more mpg. The Pan 13 is appreciably less HP and is closer on mpg.

It surprises me really as I expected "better" from the Japanese techno wizards

[McBoxer]

It surprises me really as I expected "better" from the Japanese techno wizards

That may well be what I was trying to say all along! Doesn't help with your road tax though.......

[conkerman]

I have no experience of the other bikes but know a little about the K motor.

Its the future really. Fly by wire, knock controlled, no user servicable parts inside

[bikesnbones]

Don't forget the effect of aerodynmaics.
Any bike, no matter how well faired, is an aerodynamic nightmare.
Stick a rider on board, and the problem is doubled.
Of course this only excuses low mpg at constant motorway speeds.
Not in town.

[nab 301]

(there are some really shocking figures coming back on the Ford 1litre 'ecoboost' with 125bhp - with many owners reporting 35mpg averages)

Much better than the late teens mpg the company MK1 fiesta 1.0l and mk2 escort 1.1 returned in the early 80's....

[Gromit]

Don't forget the effect of aerodynmaics.
Any bike, no matter how well faired, is an aerodynamic nightmare.
Stick a rider on board, and the problem is doubled.
Of course this only excuses low mpg at constant motorway speeds.
Not in town.

Exactly.

I had this discussion with a non-biking friend some time ago, who was asking what the performance of my Blackbird was like against modern supercars. I stated that on acceleration, it would take a very serious car to even get anywhere close to it from a *rolling start up to 140mph or so. I then explained its power/weight ratio and the peformance potential hits home (ie 145-150bhp at the wheel pushing 220kg or so) ie 650+bhp/tonne.

However, its top speed is nothing like what one would imagine it should be, bearing in mind the power to weight. There are many cars going a fair bit quicker, on a much lower power-weight.

Said friend was slightly baffled at this but it's simple - as BnB said, bikes' aerodynamics are pretty dreadful. Above 100mph, a huge amount of the engine's oomph is taken just to battle against the drag of the air. Cars win back very convincingly.

*I say a rolling start as cars are a darn sight easier to get off the line with their traction/launch controls etc.

[bikesnbones]

Don't forget the effect of aerodynmaics.
Any bike, no matter how well faired, is an aerodynamic nightmare.
Stick a rider on board, and the problem is doubled.
Of course this only excuses low mpg at constant motorway speeds.
Not in town.

Exactly.

I had this discussion with a non-biking friend some time ago, who was asking what the performance of my Blackbird was like against modern supercars. I stated that on acceleration, it would take a very serious car to even get anywhere close to it from a *rolling start up to 140mph or so. I then explained its power/weight ratio and the peformance potential hits home (ie 145-150bhp at the wheel pushing 220kg or so) ie 650+bhp/tonne.

However, its top speed is nothing like what one would imagine it should be, bearing in mind the power to weight. There are many cars going a fair bit quicker, on a much lower power-weight.

Said friend was slightly baffled at this but it's simple - as BnB said, bikes' aerodynamics are pretty dreadful. Above 100mph, a huge amount of the engine's oomph is taken just to battle against the drag of the air. Cars win back very convincingly.

*I say a rolling start as cars are a darn sight easier to get off the line with their traction/launch controls etc.

When I had a ZZR1100 back in 1996 I thought I was King of the road, until the day I got into one of those stupid willy waving competitions with a guy in a Subaru Impreza Turbo on the M2 to Kent.
That was the day I learned that top speed on paper is one thing, but in the real world, it's dependent on so many factors which fast cars are largely exempt from.
That Impreza blitzed me.
Glad to say I've grown up since then, and my philosophy now is, if I want to go fast in a straight line. I'll catch the train.