Aggressive drivestyle

[i-DSi]

Hi all,
Strange: last tank I emptied with my CBF600S (see gaslog) is only 4% less mpg. Allthough I drove at least 50% this time very aggressive: hard acceleration, braking and very high revs (hit the limiter by accident a few times) where possible. On top of this: I didn't drove the bike in wintertime, so some fuel could even evaporate.
I know that one fill doesn't mean that much, but if you have a look at my both vehicles gaslog you see that my fuel consumption can be called 'very stable'. Especially for daily commute with the motorcycle.
What disappoints me a bit: drivestyle doesn't seem to influence consumption that hard on my MC. My best MPG ever was one fill emptied in one time and also than drivestyle was not 'economic'.

[cat0020]

Hard acceleration as in over 10,000 rpm?

I remember riding my 1990 CB-1 aggressively on some rides, cruising at 10-11,000 rpm on the highway at 85-90 mph... the little in-line 4 engine still managed over 45 mpg.

[i-DSi]

Originally Posted by cat0020

Hard acceleration as in over 10,000 rpm?

Yes, limiter comes in at 12.500. Max power is at 10.500 rpm, max torque is 8250 rpm. That's where you want to be for some fun. I thought it was going to ruin my FE completely, but it didn't.

[Jay2TheRescue]

It may be that your bike's motor is more efficient at higher RPM's. I know this is the case with my 4x4.

[alvaro84]

And what if you drive conservatively - but at higher rpms?

Sounds interesting and disappointing at once. But there should be a key to get better FE, shouldn't be?

I wrote too much and deleted it, and I'll try to summarize it shorter...

Teresa (650cc) can get the best by highway P&G for sure (down to 2.38l/100km, my best ever), 'bottom of 5th' still CAN give under 3l/100km, and going faster gradually gets worse (kind of 3.35l/100km when we had ~20-25% of 110-130 stages, 2-up with luggage, a bit better when I only rode at 110 in the 130 stages) - but I don't know how 'unnecessary' revving would affect my average, that feels dirty, stupid and un-classy for me - but going in lower gears gets worse results for sure.
So for Teresa the key is giving her load and coast the rest, constant speed at low revs is only second to it. Driving with load seems useless.

Ciliegia (250cc) is different in a very logical way: her gearing is shorter and her engine is weaker so she enters the efficient range more easily. Going at the bottom of 5th clearly beats highway P&G with her. And city driving seasoned with some coasting doesn't hurt her FE at all.

I'd conclude that your CBF is even more 'agressive' than Teresa and the stronger engine hungers for load even more - or something similar I don't know what the heck I can think about its immunity to high revs though... it would be sooooo good to see BSFC graphs for motorcycle engines too...

[theholycow]

Originally Posted by alvaro84

there should be a key to get better FE, shouldn't be?

The only key is this: Track your energy. Know how your energy is made, know when you're using energy, know where it goes, and know when you're discarding energy.

[i-DSi]

At this moment I'm driving again 'normal' (=fuel efficient).
In my case: I give the engine 'load'. But most of the time this is at rather low rpm in daily traffic. And I'm sure I don't overload the engine, I'm far from 50% throttle opening.
But as you say Alvaro: it's disappointing and interesting at the same time.
Theoretically driving at higher rpm's with less load is not fuel efficient. Load is theoretically the keyword for good fuel economy. I never tried P&G with this bike.
I'm very curious for next fill up. Will go quick now I drive her daily again.
It should come back to the very normal baseline for daily commute as usual (a few % less good than getting everything out of the little 16V....)

[alvaro84]

(I got the average for my last tank - it's awful, 3.47l/100km well, we went at 130km/h for quite a while and air drag is no joke here - I think I did not say anything new... and it won't be my normal riding style, I can easily promise...)

[alvaro84]

i-DSi, if you're here, your theory about the different strength engines at different speeds now has some supporting data.
We had a longer (mostly freeway) trip to Slovenia with the 2 bikes and while it's easier to obtain good FE with the 250cc, 27hp Ciliegia at low speeds, Teresa won this round hands down, even though our pace was quite moderate (mostly 100-110km/h [62-68mph] by the speedo, sometimes up to 120, but kept the 130km/h [81mph] speed limit even at passing trucks). Ciliegia went up to 3.64l/100km while the 650cc, 50hp Teresa was hardly worse than under 90km/h, she could do this first, fastest segment with a fuel consumption of 3.17l/100km.

And, as my previous post shows, Teresa gets worse by 130km/h (81mph) too.
There was another longer trip in between, usually at 100km/h on the freeway, but in strong head/sidewind all the way. Now that was even worse than the 130km/h one...

[cat0020]

Alvaro84, are the fuel consumption averges for your motos calculate with kilometer or mile, gallon or liter of fuel consumed?