[tahoest2]

Just did several hundred miles of touring in Northern CA. As an experiment I used 87 octane the whole way, read a few articles about getting better mileage with it over 91-so I tried it.

Here's what I found.

I live in Tahoe at roughly 6000 feet. My shorter rides consist of 55mph zones, normal canyon riding. Dropping to maybe 4000 feet in elevation. Bags attached but empty. I was getting 37mpg with 91 octane. Speeds general kept below 80mph. Fairly open twisties.

On my trip, I ran 87 octane with about 15lbs in each side bag and a small tank bag. Went from 6000 feet to sea level Saw speeds as high as 120 and seemed to be traveling in the 75-85mph range on the straights/freeways and mixed in a lot of sharp turns(near stop/starts). One tank I saw 41mpg and all others were 37 or slightly higher.

Not sure what it all means, but there it is....

 

[Gearbox]

I just came back from Germany where used the lowest rating all the time and was questioned by my BMW riding pals whether it was good for the engine as they always put in the highest (The GT's actually recommended).
Fuel ecomnomy was great and on the rare occasions I have put higher octane in the engine has responded worse. Even had the PC3 set up with low octane and she made 113 bhp/74 lblt so was still making good power.
Not sure why but I always stick with the cheap stuff (Although a good supplier (BP-Shell etc) even though its 4 valve head.
Was two up with panniers , 52 L topcase and tank bag and on the last sqirt & dash fill-up went 80 Miles on 6 Litres giving 60 mpg which cant be bad !

 

[Derek]

I've always run 95 octane UK fuel which is probably the equivalent of 87 octane US fuel (they use a different rating system, RON & MON. I can't remeber which is which). There is nothing to be gained by using a higher octane unless the engine is prone to detonation. A lower octane fuel will burn better.
Consumption has varied from 45mpg to 63mpg depending on how I'm riding. Thes figures are for imperial gallond so that would be 36 to 50mpg US.

 

[Lesco]

lol .... leave it to a couple of Scots to use the lowest octane/cheapest gas they can find.
I generally use mid-grade or premium in the ST2. I just tried a tank of that new premium gas being hyped by Shell and appear to be heading for a 400 km tank! Haven't figured out the mileage yet but will probably refill on the way home from work & let everyone know.
Cheers;

 

[Stick]

A couple of comments:
Premuim fuel IS NOT recommended...due to it's "controlled burn rate", it tends to leave residues (carbon). Use the lowest octane available as long as you don't get knock/ping.

My ST2 got better mileage on trips vs. local commuting. Trips approx. 50mpg or above vs. 40 or less for local.
ST4S's seem to get great economy. I'm up in the 50's for commuting. My friend has a 2002 ST4S, and he has noted the same. I'm running (ran) regular 89 octane in the
ST4S (and the ST2).

 

[tahoest2]

Okay, what gives? How on earth are folks getting 50mpg on an ST2? What am I doing wrong? I get high 30's to low 40's. "Maybe" 45 on one tank.

 

[RedST]

Against logic, the ST4s gets better mileage than the ST2.

Mine averages 40-50 MPG around here.

The 4-valve head must be more efficient, or the injection is better. Or that the gearing on the 4s (15-38) it just taller by default than the 15-42 on the ST2.

The SC (DS 1000) gets barely 130Mi out of a 4 US gallon tank.

 

[tahoest2]

Stick above says:

My ST2 got better mileage on trips vs. local commuting. Trips approx. 50mpg or above vs. 40 or less for local.
ST4S's seem to get great economy. I'm up in the 50's for commuting. My friend has a 2002 ST4S, and he has noted the same. I'm running (ran) regular 89 octane in the
ST4S (and the ST2

Just can't fathom getting 50mpg with my st2...I'd be happy with mid 40's. Maybe it's because I don't have any 55-65mph normal highway riding to compare too?

 

[Lesco]

Stick, not sure about your claim that higher octane fuel leaves more carbon deposits.... but I do agree that higher octane can be "wasted" on an engine that can't use it. I think that mid-grade is closest to what Ducati recommends for the ST2 and I find my gas mileage is better with it compared to regular. I also think that you get a superior additive package with premium fuels compared to the el cheapo stuff.
fwiw

 

[Gearbox]

Stick above says:

My ST2 got better mileage on trips vs. local commuting. Trips approx. 50mpg or above vs. 40 or less for local.
ST4S's seem to get great economy. I'm up in the 50's for commuting. My friend has a 2002 ST4S, and he has noted the same. I'm running (ran) regular 89 octane in the
ST4S (and the ST2

Just can't fathom getting 50mpg with my st2...I'd be happy with mid 40's. Maybe it's because I don't have any 55-65mph normal highway riding to compare too?

As Derek says dont forget the difference of UK v US Gals.
My usual cruising speed is 75-80 mph and we dont have many patrol cars up here and few DCW's or Motorways either.
As I have posted elsewhere I believe it is all to do with avoiding large throttle openings that rely on the torque instead of being in a responsive rev-range.
Not trying criticise anybody's rding style , some like to use the V-Twin grunt but economy suffers as a result.

 

[Stick]

On my old BMW, that had 100,000 +- miles on it, using regular. No valve recession issues.
The ST2 had 52,xxx miles on it. 49K mi. were mine, using regular. No issues, no pinging, heads never off.
Even my '81 Pantah--regular. And that beast was similar: better MPG at 80 mph than casuall commuting miles.
And all these bikes were ridden with a "happy wrist".

 

[Lesco]

Just checked the mileage on the last tank ..... 52 miles per US gallon. Riding was all two-lane blacktop recreational riding mostly at 70mph'ish+. My ST2 has about 24,000mi on it but the engine is pretty fresh with an MBP Ducati tune up and valve job. Oh yeh, it is chipped, has the airbox opened up and has FBF exhaust too.

 

[tahoest2]

Um, I must be doing something wrong.... 37-45 is a LONG way off from 52.... Are you at sea level? I'm sure that has some effect v.s. riding at 6,000 feet?

I have not done a straight two lane highway stretch on my bike yet. Almost all canyon roads. Though, my last ride before hitting the shop was on 101 south in CA. I didn't fill up before dropping off but I did notice that at just one/two bars below 1/2 I was at 130 miles. And in the past, my fuel light is usually on at 130/140 miles. So maybe I did hit more the high 40's or low 50's on that tank while riding at normal and consistent cruising speeds.

I know others somewhere say something about a possible fuel leak if mileage is really poor. But, unless it's leaking while riding I don't see any fuel anywhere in my garage, no odor, etc.. I do have a bit of bubbling from time to time out of the keyhole in the tank.

 

[captaingumby]

Even if you had a leak that only happened when moving you would know. I once had a carb float that was just a little off a caused fuel to leak out the overflow when heading up hill. I would smell the gas when I stopped.

 

[cb4265]

2002 ST2 Owners manual says 95 octane as recommended;

 

[Lesco]

Not sure how far above sea-level we are ..... Eastern Ontario. Certainly not 6000ft! Having Guy Martin at MBP do the tune-up may have alot to do with it.

Yeh, the manual states 95RON minimum octane.....which in N.America would be around 92'ish. Mid-grade.