Go Back   Horizons Unlimited - The HUBB > Technical, Bike forums > Tech
Tech ALL bikes: "Generic" tech questions and answers. Maintenance, general discussions etc.
Photo by Daniel Rintz, Himba children, Namibia

The only impossible journey
is the one
you never begin

Photo by Daniel Rintz,
Himba children, Namibia



Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 30 Aug 2010
Chris Scott's Avatar
Super Moderator
Veteran HUBBer
 
Join Date: Jun 2000
Posts: 4,801
fuel consumption in different power modes

It looks like many new Adv bikes are coming with 2 or 3 power modes.

Never ridden one myself but I wonder if anyone's established whether fuel consumption varies much in these modes. After all, some drop power by 30%.
Could that mean 30% better economy? My impression is a low compression ratio and normal power (< 100hp/litre) often adds up to good mpg, carb or efi.

I imagine for overlanding after a while you'd put your 600cc+ bike on the lowest power mode.

Chris S
Reply With Quote
  #2  
Old 30 Aug 2010
Registered Users
Veteran HUBBer
 
Join Date: Apr 2008
Location: West Yorkshire UK
Posts: 1,785
I hope someone has established the numbers. There is no reason these bikes shouldn't turn in 70 mpg at real world speeds (Ted Simons Jupiter was capable of this in 1973). If the modes are just fast acceleration/studpidly fast acceleration/Impress the journalist acceleration there is going to be a gap in the market for chips/patches with a proper economy mode.

Still, what do I care, the brick seems to do 30 mpg regardless, but it does have a fridge and somewhere to stow the gin

Andy
Reply With Quote
  #3  
Old 31 Aug 2010
Mickey D's Avatar
Moderated Users
Veteran HUBBer
 
Join Date: Jan 2010
Location: California
Posts: 501
I recently rode the new Ducati 1200S Multistrada. We tried the 3 power modes but never kept track of fuel economy. (we only got it for a day) But MCN (American magazine, not the UK Scandal sheet) did test the economy as part of their testing. In low power the Multi got 42 mpg (US gallons) which did not compute to the 15% improvement Ducati claimed in low power mode. I liked full power mode best, had the best drivability.

The BMW is most likely better, as they do seem to get fuel economy right.
No idea on the new Yamaha 1200 Tenere'.

I can't believe that about the best I can get on my DR650 Suzuki is 50 mpg (US gallons). Now that is a bike that would benefit from F.I. Seems even if I'm pooching along at 45 mph and never goose it ... it still doesn't get much above 50mpg. Head winds and deep sand and even panniers suck gas. Add a typically overloaded bike and your predicted range is shot.

I could take a 250 or 400 but I'm too old and too spoiled by the comforts of my DR. I love the 250's in technical stuff, sand, mud, rocks. I love the 70 mpg. But over all, as a day-in-day-out travel bike ... for me? No joy. Just have to pay the price and plan carefully regards range and attempted destinations.

Last edited by Mickey D; 1 Sep 2010 at 06:46.
Reply With Quote
  #4  
Old 31 Aug 2010
Robbert's Avatar
Contributing Member
Veteran HUBBer
 
Join Date: Sep 2001
Location: Gent, Belgium
Posts: 523
Compression

Quote:
Originally Posted by Chris Scott View Post
My impression is a low compression ratio and normal power (< 100hp/litre) often adds up to good mpg, carb or efi.
That I guess has more to do with the overlap of the valve timing (time that both inlet and exhaust valves are open). I expect there will be a correlation between compression and valve overlap. High compression and little overlap should result in best fuel economy.
Reply With Quote
  #5  
Old 31 Aug 2010
Chris Scott's Avatar
Super Moderator
Veteran HUBBer
 
Join Date: Jun 2000
Posts: 4,801
42 US for the Ducati = 50.4 Imp. MPG or 17.8 km/litre. *

Looks pretty good to me seeing as a recent Brit mag came up with 37 Imp. MPG (30.8 US!) in high power for the Multistrada.
And they said the new Yamaha 1200 Tenere was worse! It does weigh over quarter of a tonne, but can that be possible?

Never thought of valve overlap; it does seem like a recipe for wasting fuel. Do most modern high-revving engines have more overlap then an old BSA 21 for example?

Even then, I've always thought an advantage of low comp for overlanding is an ability to run OK on low-octane fuel.

That's assuming you can't electronically retard the ignition as you can on some bikes since many years. Is that what a low power mode will be on these latest bikes? Or is it lots of things in the system from throttle to exhaust?

Chris S

* Good converter here
Reply With Quote
  #6  
Old 31 Aug 2010
AliBaba's Avatar
Registered Users
Veteran HUBBer
 
Join Date: Apr 2001
Location: Norway
Posts: 1,379
Quote:
Originally Posted by Chris Scott View Post
Never thought of valve overlap; it does seem like a recipe for wasting fuel. Do most modern high-revving engines have more overlap then an old BSA 21 for example?
Old engines generally have less overlap.
I wouldn't say that increased overlap has to increase fuel-consumption. It might increase, but it can also decrease. Personally I think choosing the right cam-shaft is a very important task to fit the bike to your needs. I will soon test another camshaft with more overlap.


Quote:
Originally Posted by Chris Scott View Post
Even then, I've always thought an advantage of low comp for overlanding is an ability to run OK on low-octane fuel.
Yes, with low compression you can run low-octane fuel but the engine will not be efficient and it will use less fuel if you increase compression.
There is quite a few things you can do to keep compression up (and running lean) without getting problems. Newish bikes generally have higher compression then the old ones.
Increasing overlap will help you to run on low-octane fuel and it will also allow higher compression, nice!
A single-cylinder engine will suffer more then a multi-cylinder engine when it comes to low-octane.

Quote:
Originally Posted by Chris Scott View Post
That's assuming you can't electronically retard the ignition as you can on some bikes since many years. Is that what a low power mode will be on these latest bikes? Or is it lots of things in the system from throttle to exhaust?
Retarding the ignition will increase fuel-consumption. Best fuel-consumption (and power) is achieved when the ignition is a bit more retarded then where it's starts to knock. The way BMW has solved this is to install a knock-sensor, ignition is then adjusted based on the knock-sensor (and other parameters).
Reply With Quote
  #7  
Old 31 Aug 2010
Registered Users
Veteran HUBBer
 
Join Date: May 2007
Location: yorkshire
Posts: 362
Hi Chris.

Do you mind me asking...What MPG did you get out of your Tenere XT660Z on your trip to Morocco.

Dazzer
Reply With Quote
  #8  
Old 31 Aug 2010
Chris Scott's Avatar
Super Moderator
Veteran HUBBer
 
Join Date: Jun 2000
Posts: 4,801
It's all here Daz, in excruciating detail:

XTZ660 Tenere review - fuel consumption data

A single-cylinder engine will suffer more then a multi-cylinder engine when it comes to low-octane.

I remember in the 1980s some singles ran terribly on Algerian fuel: my XT500 one time - and later a Honda XLM was much worse than 2nd gen. Teneres. I suspect fuel has got a bit better since then.

Chris
Reply With Quote
  #9  
Old 31 Aug 2010
Registered Users
Veteran HUBBer
 
Join Date: May 2007
Location: yorkshire
Posts: 362
Thanks Chris

Nice to see that I'm not alone in logging the bike's fuel consumption on a trip.

Now don't set me off talking about Tyre wear


chug Dazzer
Reply With Quote
  #10  
Old 31 Aug 2010
*Touring Ted*'s Avatar
Contributing Member
Veteran HUBBer
 
Join Date: Jul 2005
Location: Wirral, England.
Posts: 5,654
It's pretty impossible to factor in the most important variable though isnt it !!

Riding style !! You can get HUGE differences just on how smoothly you accelerate, if you have a heavy wrist, if you power through or roll the corners etc etc.

Back to the point Chriss, I think the manufactures promo brochures often have the average economies in the different modes. If you believe them that is !!
__________________
Did some trips.
Rode some bikes.
Fix them for a living.
Can't say anymore.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 Registered Users and/or Members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
LC fuel consumption gren_t Light Overland Vehicle Tech 12 7 Jun 2011 10:06
fuel consumption spiro Equipping the Overland Vehicle 10 10 Mar 2010 19:29
Fuel Consumption highway Yamaha Tech 2 22 Dec 2003 17:50
HELP! - No Power, big fuel consumption, overheating Fuchur Yamaha Tech 5 9 Jan 2003 21:18
Fuel consumption mudlark Yamaha Tech 1 5 Dec 2002 21:24

 
 

Announcements

Thinking about traveling? Not sure about the whole thing? Watch the HU Achievable Dream Video Trailers and then get ALL the information you need to get inspired and learn how to travel anywhere in the world!

Have YOU ever wondered who has ridden around the world? We did too - and now here's the list of Circumnavigators!
Check it out now
, and add your information if we didn't find you.

Next HU Eventscalendar

HU Event and other updates on the HUBB Forum "Traveller's Advisories" thread.
ALL Dates subject to change.

2024:

Add yourself to the Updates List for each event!

Questions about an event? Ask here

HUBBUK: info

See all event details

 
World's most listened to Adventure Motorbike Show!
Check the RAW segments; Grant, your HU host is on every month!
Episodes below to listen to while you, err, pretend to do something or other...

2020 Edition of Chris Scott's Adventure Motorcycling Handbook.

2020 Edition of Chris Scott's Adventure Motorcycling Handbook.

"Ultimate global guide for red-blooded bikers planning overseas exploration. Covers choice & preparation of best bike, shipping overseas, baggage design, riding techniques, travel health, visas, documentation, safety and useful addresses." Recommended. (Grant)



Ripcord Rescue Travel Insurance.

Ripcord Rescue Travel Insurance™ combines into a single integrated program the best evacuation and rescue with the premier travel insurance coverages designed for adventurers.

Led by special operations veterans, Stanford Medicine affiliated physicians, paramedics and other travel experts, Ripcord is perfect for adventure seekers, climbers, skiers, sports enthusiasts, hunters, international travelers, humanitarian efforts, expeditions and more.

Ripcord travel protection is now available for ALL nationalities, and travel is covered on motorcycles of all sizes!


 

What others say about HU...

"This site is the BIBLE for international bike travelers." Greg, Australia

"Thank you! The web site, The travels, The insight, The inspiration, Everything, just thanks." Colin, UK

"My friend and I are planning a trip from Singapore to England... We found (the HU) site invaluable as an aid to planning and have based a lot of our purchases (bikes, riding gear, etc.) on what we have learned from this site." Phil, Australia

"I for one always had an adventurous spirit, but you and Susan lit the fire for my trip and I'll be forever grateful for what you two do to inspire others to just do it." Brent, USA

"Your website is a mecca of valuable information and the (video) series is informative, entertaining, and inspiring!" Jennifer, Canada

"Your worldwide organisation and events are the Go To places to for all serious touring and aspiring touring bikers." Trevor, South Africa

"This is the answer to all my questions." Haydn, Australia

"Keep going the excellent work you are doing for Horizons Unlimited - I love it!" Thomas, Germany

Lots more comments here!



Five books by Graham Field!

Diaries of a compulsive traveller
by Graham Field
Book, eBook, Audiobook

"A compelling, honest, inspiring and entertaining writing style with a built-in feel-good factor" Get them NOW from the authors' website and Amazon.com, Amazon.ca, Amazon.co.uk.



Back Road Map Books and Backroad GPS Maps for all of Canada - a must have!

New to Horizons Unlimited?

New to motorcycle travelling? New to the HU site? Confused? Too many options? It's really very simple - just 4 easy steps!

Horizons Unlimited was founded in 1997 by Grant and Susan Johnson following their journey around the world on a BMW R80G/S.

Susan and Grant Johnson Read more about Grant & Susan's story

Membership - help keep us going!

Horizons Unlimited is not a big multi-national company, just two people who love motorcycle travel and have grown what started as a hobby in 1997 into a full time job (usually 8-10 hours per day and 7 days a week) and a labour of love. To keep it going and a roof over our heads, we run events all over the world with the help of volunteers; we sell inspirational and informative DVDs; we have a few selected advertisers; and we make a small amount from memberships.

You don't have to be a Member to come to an HU meeting, access the website, or ask questions on the HUBB. What you get for your membership contribution is our sincere gratitude, good karma and knowing that you're helping to keep the motorcycle travel dream alive. Contributing Members and Gold Members do get additional features on the HUBB. Here's a list of all the Member benefits on the HUBB.




All times are GMT +1. The time now is 19:04.