Premium Fuel Only (?)

On my recent tour of Eastern Canada (and some Eastern US states) I ran my ST through the whole fuel grade spectrum, from low grade 87 from sketchy gas bars to high grade 94 at some of the largest fuel suppliers in North America. 80% of the time I was running fuel with ethanol but for the 20% of the time when I was using ethanol free premium fuel this produced the best fuel economy for my ST. I haven’t worked out the “bang for the buck” yet but as far as getting further down the road, ethanol free premium did the trick.
What I found most interesting was that as I ran the spectrum, I found no “noticeable” performance issues either way. No poor performance or pinging when using regular and no jump or extra zip when using premium.
FWIW, I believe that if you are using fuel with ethanol, and most of us are, as long as you are burning this fuel regularly (i.e. not letting the fuel sit in your ride) and keeping it fresh in your tank, I doubt fuel quality problems will show up. That being said, I do the same as @Bmacleod with regards to storage prep for the winter. Ethanol free through the fuel system. YMMV.
 
I got my 2007 ST-1300 used the day before Thanksgiving this year. It didn't come with an owners manual or shop manual but I have since acquired both from another helpful user of this website that was selling those books and other accessories for ST 1300's.

The last two owners of this bike rarely used it -- actually the most recent guy never used it other than the initial ride to get it to his house. They both had other motorcycles they preferred more.

They told me they both used only premium fuel in it, and if I were only gonna go through less than one tank of gas a year I wouldn't mind paying the extra cost!!!


I just now, TONIGHT, got to reading that part of the owners manual where it says to use 91+ octane unleaded gas.


THE COST: right now here in the state of Georgia the price difference is about $.90 per gal. It's $2.95 per gallon for 87 octane gasoline with 10% blend of ethanol .
It's $3.85 for premium fuel with 91- 93 octane rating (but still blended with ethanol.)

I put 11,000 miles on my Honda shadow over the last 11 months, so if I can save nearly a dollar per gallon buying cheaper gas, this will add up to real savings for me.

If I ride the ST-1300 for 12,000 miles in 2025 and if I get an average of 36 mpg combined city and highway riding (I'm a heavy guy so I'm sure this affects fuel mileage somewhat) I'd use up 333 gallons.
Saving $300 a year is nice.

I've only burned through one tank of gas so far and that tank of 87 octane gas got me 36 MPG average.

QUESTION FOR YOU ALL: If I were to use premium gasoline and change nothing else about how I ride or where I ride what do you think would happen to my average fuel economy? Would it go up from 36 MPG? How much better would it get?

TOP SPEED AND TORQUE PERFORMANCE DOESN'T MATTER, I am more interested in quiet, gentle acceleration, vibration free cruising in the fast lane, low noise, riding up to several hundred miles per day.

I'm not concerned with doing 0 to 60 MPH or 0 to 100 runs while looking at a stopwatch.
 
I run 86/87 octane E10 most of the time in my STs. One of mine (a 2007 I bought several years ago here locally) has averaged 48.5 mpg since I've owned it figured on 180 gallons of gas through it. My recently acquired 2007 from Shuey/IGOFAR has averaged 42.1 mpg over the 39 gallons of 87 I've run through it.
 
Larry Fine said:
A lower-than-ideal-octane fuel will result in knock in carburetor-equipped engines that need more, and reduced power in fuel-injected engines with knock sensors.

A higher-than-needed-octane fuel will not produce any more power.

ST1100's are rated for regular, ST1300's are rated for premium. It's primarily based on the compression ratio.
Click to expand...
 
Manual says 95 octane RON minimum. That is the regular standard in the Uk, and the ST1300 is Ok on that with 10% ethanol.
The bike certainly runs nicer on premium 99 RON with little or no ethanol, and I give it a treat every few tankfuls. Mpg is slightly higher as shown on the average consumption display. Thats not an issue. But the smoother running is nice.
With my 2006 ST1300, it ran badly in Europe with the E10 fuels: Pinking mildly (weak mixture) under load and acceleration. The higher octane fuels and fully synth oil cured that - don't know why the combination with the expensive oil worked, but it did.

95 RON uk = 91 PON usa. = 87 MON
98 RON uk = 94 PON usa = 90 MON

(According to a google search)

The bike loves the colder mornings, slightly damp air. High barometric presure / Denser air = more oxygen per lungful. I don't know how the damp works - extra steam power ? In the Dales we get lots of temperature inversions where the cold damp air sinks to the bottom of the valleys overnight. Its always good to give the bike a run on those mornings.

In the good old days, Dad used to tell me that some people fitted a device that sprayed a water mist into the air inlet or the carb inlets to improve the way that the engine ran. Dad also told me about santa claus of course.
 
Last edited:
@jfheath Got to agree about smoother running in cooler conditions, also smoother with V-Power (premium fuel). Absolutely no scientific proof, just the feeling through the bars and footrests.

jfheath said:
Dad also told me about santa claus of course.
Click to expand...

So your Dad was always right!! 'cos Santa is real :D at least in my house...... and as my wife constantly reminds me I'm 69 going on 6 :redface:

ps first grandchild due on the Winter Solstice (21st Dec). Looks like the sidecar may come back into use properly :giggle:
 
The ST1300 engine has knock sensors and will run just fine on Georgia-sourced regular gas. Don't worry about "wearing out" the knock sensors on regular. Digital devices don't work like that. The spark timing will be retarded slightly to account for any pre-ignition that might occur with regular gas during high power settings at low rpm. Thus the engine will produce slightly less power.
 
What's your owners manual say about fuel octane requirements? Go by what the manufacturer recommends.
Using high octane fuel in a machine designed for lower octane engines is a waste of money. It doesn't burn any "hotter" or "cleaner".
 
You must log in or register to reply here.
Back
Top Bottom