Amazing fuel consumption

[oldrascal]

Until a few weeks ago, I hadn't bothered taking off the aluminium panniers from my 2008 GSA and rode with the full set including top-box. During this period, my average consumption was around 45mpg.

A couple of weeks ago, I decided to leave the panniers in the garage and I now ride with just the top-box fitted. Yesterday, I checked my fuel consumption which has now dropped to 53mpg.

I ride the same way so either the computer is on the fritz or the panniers are a real drag in the aerodynamic sense. What is the general experience of with and without pannier consumption? And if I were to take off the top box, would it be better still?

 

[Big Lee]

Well I can`t say I`m surprised, with 2 great big flat faced boxes in the wind they`re bound to create some drag

 

[bumpy]

My GS with top box returns 55mpg

 

[oldrascal]

I accept that a certain amount of extra drag is going to harm consumption - but by as much as 8mpg? That's huge. As the GSA already has the aerodynamic efficiency of a large barn door and the panniers are in any case partly shielded by the rider's legs, it still seems a lot.

Also, Bumpy, I can't work out why you are getting so much better economy than me unless my Akropovic can has a bearing. Mysteries, bloody mysteries.

 

[TLSgazza]

well mine returns an average of about 41.5 MPG (with both of the panniers fitted) according to the computer, mind you in the alps last year with all the camping gear on board i averaged 52, go figure,
got a service next week so it will be interesting to see if it improves

 

[CJ.]

Went down to West Bay last weekend on the GSA with the better half, and a top box !! covered about 150 miles, ave fuel consumption 54 mpg. Happy with !!

 

[RickG]

It depends how fast you ride, but big ally panniers act like additional barn doors and will knock the fuel consumption way down if you're spending most of the time cruising on a motorway at 80mph or above. If you are on a slow twisty road they will have far less affect. Absolutely no surprise to get better than 50mpg on a fast trip without panniers but 45 or worse on the same journey with them on. Top box probably makes far less difference as it's in the lee of yourself, may even help actually...

 

[turnipbmw]

my new 1200 is showing 48.7mpg unyet I put in 14 litres to do 185 miles which sounds nearer 60

(which is what my 06 1200 would do at times)

Will have to try a scientific study

 

[Kaybe]

If you remember a few years ago when there was a craze for sticking small flags out the window of cars.
Although these were quite small it was estimated they were reducing fuel consumption by 2%, so I would think that the panniers could easily be c10%.

 

[Fanum]

I seriously worry about people who know their bike's MPG to within half a mile per gallon.



Well actually no, I don't.....but perhaps they should worry about themselves


FFS

 

[autogs]

I seriously worry about people who know their bike's MPG to within half a mile per gallon.



Well actually no, I don't.....but perhaps they should worry about themselves


FFS

quite but at least he dosent write in fecking blue anymore

 

[bumpy]

I seriously worry about people who know their bike's MPG to within half a mile per gallon.



Well actually no, I don't.....but perhaps they should worry about themselves


FFS

Its all on the computer

 

[oldrascal]

Cheer up Autogs, just think if I batted for the other side and wrote in pink. Anyhow, my screen is running out of blue colour pixels and sometimes defaults to black so you might get a good night's sleep at last.

 

[GSband]

While riding with side panniers, put your left hand just alongside (or in front of, or on top of) the left hand side pannier. You'll feel how the wind blasts onto the panniers. Quite impressive.

As the OP stated, there IS a huge difference in fuel consumption (and performance, BTW) with/without side panniers. I usually ride with topbox only.

 

[Wapping]

Why not just put the damned panniers back on? Ride around for six months (or hopefully longer) and report back. That should settle your MPG question, leaving aside any other variables.

What intrigues me is why have the detachable panniers on at all, when they are empty? Is it to create the global traveller impression?




Correction. That doesn't intrigue me at all.

 

[oldrascal]

I am not sure why any conversation about panniers or Rallye Pro 3 kit is bound to bring up the hoary old chestnut of trying to look like a global traveller/Charlie-Ewan wannabe.

The point is that most of us revel in the pleasure that the GS brings and part of that pleasure is its massive road presence which is not only a major safety point but is also tittilatingly and smugly satisfying. And there is no doubt that a pannier-equipped GSA is even more imposing and noticible. So what does that prove or disprove? Nada.

Whether you ride with the panniers on or off should be purely a matter of personal preference and if there are those who prefer the looks with the panniers fitted, why not? I find them bloody useful even for local trips as I can leave the helmet in the topbox, a rainsuit, first-aid kit, fluo jacket and safety chain in one of the panniers leaving the other free for shopping or WHY.

My only comment was based upon a trip of 50 miles or so without the panniers and the surprising diference in fuel consumption. Now that's a valid point of discussion I reckon.

 

[birdseye]

panniers are bound to cause a fair bit of extra drag, but a reading off the computer is not an accurate way of determining fuel consumption. you need to do several tank fulls and average it out.

I'd be surprised if the difference was as big as that

 

[Wapping]

I am not sure why any conversation about panniers or Rallye Pro 3 kit is bound to bring up the hoary old chestnut of trying to look like a global traveller/Charlie-Ewan wannabe.

The point is that most of us revel in the pleasure that the GS brings and part of that pleasure is its massive road presence which is not only a major safety point but is also tittilatingly and smugly satisfying. And there is no doubt that a pannier-equipped GSA is even more imposing and noticible. So what does that prove or disprove? Nada.

Whether you ride with the panniers on or off should be purely a matter of personal preference and if there are those who prefer the looks with the panniers fitted, why not? I find them bloody useful even for local trips as I can leave the helmet in the topbox, a rainsuit, first-aid kit, fluo jacket and safety chain in one of the panniers leaving the other free for shopping or WHY.

My only comment was based upon a trip of 50 miles or so without the panniers and the surprising diference in fuel consumption. Now that's a valid point of discussion I reckon.

Your average fuel consumption comparison was based on what? A 50 mile journey. That's hardly are fair comparison for anything much, is it?

What's with all this 'presence' lark, beyond being wider than a FireBlade but narrower than a Ford Fiesta? Your fluo jacket is not doing much good in the pannier, is it? Better to be wearing it if you want to boost your 'presence', surely?

Your thread was about fuel consumption with / without panniers fitted. You now confess to running about with them 9/10's empty to increase your 'presence' and to some degree appeal to your vanity. But then you worry about fuel consumption. Well, my old love, 'presence' and vanity comes at a cost.

The solution is easy.

Stay as you were, going for 'presence' - and carrying your bits and bobs, including a First Aid kit and fluo jacket, like an extra from Casualty - over cost (fuel).

OR

Limit yourself to a topbox (lacks 'presence', as it is hidden behind your body, I admit) to keep your chain and bits 'n' bobs in. In the meantime, your helmet will be on your head. When you stop, take the chain out of the topbox and replace it with your helmet. The cost problem is probably solved.

If you have a desperate need to increase your 'presence' or 'pleasure' and vanity - or to carry extra luggage beyond fresh air - put your panniers back on. But trade off increased fuel consumption.

It really is that simple.

 

[oldrascal]

Hey there Wapping, calm down.....this isn't meant to be a slug-fest.
I started this thread because a 50 mile journey without panniers gave such a huge improvement in consumption over the same journey with the panniers fitted. So that's a valid discussion point I reckon as the 8mpg difference is startling to me.

But just to nail a few of your comments; I carry 2 sleeveless fluo safety jackets in the event of a roadside breakdown or worse, something that is obligatory in some European countries and not a bad idea for this one either. And I think that there is nothing wrong with being seen on the road by the 4 wheel brigade and the more lights, reflectiveness and sheer 'road-presence' that we can bring to bear to achieve this, the better. Having come from a Hayabusa, I am continually and happily surprised at how much sooner the GSA gets noticed by vehicles in front - and that can't be bad but is clearly a function of frontal area, height and the bits (including rider and panniers) sticking up and out.

Anyhow, whether or not I choose to fit all of the kit or some of it has nothing to do with vanity (thank you) but more in the hope of identifying the cause of the mileage discrepancy mentioned. After all, 8mpg might be a relevant issue over a long distance where kit might get carried cheaper with a top-box and a seat bag for example if all of the capacity of the panniers is not needed.

And don't you think that your fellow Tossers might prefer reasoned and informed replies instead of the ascerbic and personal comments that you chose to make. Your reply has nothing to do with casting light on the cause of the difference and evrything to do with rubbishing me, it seems.

Can't understand what's got your goat; oh well, its a free forum so I'll just put it down to some friendly banter offered robustly.

 

[Wapping]

so I'll just put it down to some friendly banter offered robustly.

There you are exactly right.