Premium gas vs regular

[Scott_]

Now (at least around here in the midwest) they are starting to use blended mixes.
http://thegazette.com/2013/09/16/new-regulation-could-widen-price-gap-between-ethanol-non-ethanol-fuels/

Refineries are starting to deliver low 80's fuel and expecting the distribution terminals to either blend it with corn ethanol or with premium to make the minimum octane of 87.

[TimTyler]

... it had set in an non-heated non-airconditioned garage in wisconsin for 50 weeks ...

That's bike abuse! You should be.... errrr.... I dunno.  :nono

[stevendlarson@hotmail.com]

I know this is an old post I'm replying to but here it is anyway.  I run Turbo Blue Fuel, 116 Octane in my 1986 K100 RT.  I get about 220 miles per tank and it runs awesome.  At the time of this post it is costing  me about $8.25 a gallon.  It seems to give me significantly more power and the engine growls a little meaner, which I like.

[Blue]

I use 87 or 89 octane in my K1100RS.  I get about 220 miles per tank and it runs awesome.  It seems to give me tremendous power and the engine growls like a meanie.  All for under $3 a gallon at the time of this post.

[The Mighty Gryphon]

I run 87 moonshine blend during the riding season and put the 91 moonshine free in for the winter.  I get 220 miles or more per tank, my three bikes run awesome and have excellent power.  The 16valve 100 has an awesome growl and the 75's have a beautiful snarl above 4 grand.  Right now I'm paying about $2.75 a gallon and burning about three tanks a week. 

[Laitch]

My bike runs on 89 octane gasohol. I don't want more power because that would cause me to arrive at my destination sooner and that would mean I would be riding less. The six dollars or so that I save by not buying Turbo fuel I spend on coffee, cider donut holes, 89 octane fuel and T-shirts with important messages about planet preservation and vegan eateries.

[bizzaro]

https://www.pure-gas.org/

[stokester]

All my bikes seem to run just fine on regular octane fuel but I always try to use a Top Tier branded fuel in both my bikes and vehicles.


http://www.toptiergas.com

[Nine80seven]

Huge factor cage or bike is headwind, or tailwind, and anything between.  MPG should be measured over a looooooong span.  Keep track of every gallon used all summer with beginning mileage, end with fill up, then subtract from starting mileage, divide.  Get back to us.  Also, a 2.81 FD gear helps, as does an easy throttle. 


Run it hard, mine, '84 KRS, sucks a lot of gas.  Sip it or guzzle it, what ever turns yer crank.  40 mpg is friggen great IMHO.  I always use pure gas 91 octane.  If not available, highest octane ethanol.  If I can't afford good gas, might as well hang it up. 

[Laitch]

Huge factor cage or bike is headwind, or tailwind, and anything between.   

Let's call the anything between abdomino-thoracicwind.

[White Dog]

I filled the brick up with 90 octane 100% gas tonight--$3.609 per gallon.  Last time I bought gas at that place it was $3.109.  They apparently haven't gotten the email from big oil to lower their price to pre-hurricane pricing.  (Big oil probably hasn't sent that email yet.)  The price for regular 87 non-corn is $3.059, but the handle was covered with a bag.

[rbm]

I wouldn't complain too much, White Dog; that's a great price compared to up North.  I just did a calculation and found out I would be paying the equivalent of $3.93 per US gallon up here in Canada.  Premium 90 at the pump in the GTA at the moment is CA$1.30 per litre.

[White Dog]

rbm.  I recently purchased and installed a new fuel sender unit and moved the geared wheel one notch CCW to delay the low fuel light illuminating.  With the flap removed from my filler cap, I put 4.0 gallons of gas into the tank after riding 154 miles and still the light did not illuminate.  I believe the capacity of my tank is the 4.2 gallon version.  So, I was doubly nervous in that the light did not come on and the tank was almost dry.  I may have pushed the limit of the fill up, as when I put it on the center stand and opened the filler cap, there was evidence where gas had slopped out of the tank.  So, when this tank is consumed, I'll probably pull the sender unit and return the geared wheel to its original position.  (Yeah, some might say to adjust it while its in the tank but fumbling with that method is how I broke off the gears of the original unit.)  While I have it out of the tank I'll test for continuity of the light circuit. 

[bocutter Ed]

I believe the capacity of my tank is the 4.2 gallon version.

Twenty-one liters coverts to 5.55 US gallon (4.6 Imp gallon).

[White Dog]

I read on this forum that BMW decreased the size of the gas tank during the 90's, so it must be true.

[The Mighty Gryphon]

I think you are thinking Imperial gallons.  The tanks hold 5.3 U.S. gallons which converts to 4.2 Imperial gallons.  You were probably reading a post by someone in the U.K. or Canada.

My bikes are '92 and '94 models.  All of them hold 5.3 gallons.  I also get a consistant 180 miles on four gallons, and the low fuel light comes on at about 190 miles.  These numbers are with the flapper removed.

[White Dog]

Mighty Gryphon, I looked in my tank last night prior to the fill up.  Gas level was at the last ripple on the bottom of the tank.  I squeezed 4.0 gallons to fill it with flapper removed.  I live in the USA, not Canada.  Wish I could get the MPG you say you get.  154 miles divided by 4.0 gallons =38.5 MPG.


The post about tank size change I remember seeing was this one from BMW MOA.   beemerguru  beemerguru is offline
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The other possibility was the change in tank capacity around '93 or so. I got a factory replacement tank when the paint peeled on a new K75 back then and immediately noticed a decrease in range.

Popped the tank off and compared it to another off an earlier K75. There was a change in the bottom design..took away about 1/2 gal.

Called BMW and got my old tank back..repainted it and got my 1/2 gal back.
Greg Hutchinson
R80G/S (4) 633CSi with 450K mile
'68 R60/2 '88 K100RS Special Edition
http://gregsgssite.shutterfly.com/

[bocutter Ed]

AFAIK there are only 2 tank sizes (anyone?). All K100 and K75RT are 22 litres, all other K75 are 21 litres. I have one without the "change on the bottom" and it doesn't fit under the K75s fairing.

[The Mighty Gryphon]

Ed, My 1994 K75 RT and S models both have 21 liter tanks.  With the flapper removed both will take about 5.3 gallons.  Never heard of a 16 liter(4.2 gallons).   I know there are several different part numbers for tanks, but I thought they were about the different mounting and the mounts for the battery covers.  The capacity and size were essentially the same for all  of them.

I do know that 21 liters translates to 4.2 Imp. gallons.  But I'm sure they don't sell gas in Imp. gallons in North Carolina.   :dunno

[White Dog]

My owners manual, page 28, indicates the tank holds 19.5 liters (5.2 gallons) and the low fuel light is supposed to come on "when approximately 5 liters (1.3 gal.) of fuel remain in the tank."  Then I saw the posting on the BMW MOA referenced above, which made me wonder.  With the first sender unit I had, the light popped on at 130 miles and I could easily go 150-160 miles before looking for a fill up.  Then, I started messing with the geared wheel in an attempt to avoid having that bright idiot light glaring at me for 20-30 miles.  That's when I stripped all the teeth off.  So, I bought a new unit and this is the second fill up since installing.  Honestly I do not recall ever putting more than 4.0 gallons in the tank, even with the flapper removed.  If there is an easier way to completely empty the tank and refill to capacity, aside from siphoning or running the fuel pump, I'm all ears.  In the meantime, let's all fill our tanks as we please and enjoy the rides!

[BlitzenGruv]

I've been using premium as long as I've owned the K. All my old British bikes demanded premium (as I remember Triumph specified 97 minimum, but that was back when premium was 100 octane.) I might try some mid grade just to see how it runs, though.
As mentioned, fresh fuel is almost mandatory. Especially with ethanol, the stuff rapidly loses its ability to ignite.
I tested samples from the different stations in the area. Most premium in the Nashville area contains about 5% ethanol. Exxon and Citgo came in lowest at about 3%.
BTW: My fuel light comes on with over 50 miles of fuel left, the gauge still reads a little under a 1/4. On the way to Barber my first stop came at 160 miles. The light had been on for about 20 miles and it took 3.4 gallons. I had been cruising at 75 to 80 with maybe 40 pounds of gear.

[K1300S]

I think you are thinking Imperial gallons.  The tanks hold 5.3 U.S. gallons which converts to 4.2 Imperial gallons.  You were probably reading a post by someone in the U.K. or Canada.

My bikes are '92 and '94 models.  All of them hold 5.3 gallons.  I also get a consistant 180 miles on four gallons, and the low fuel light comes on at about 190 miles.  These numbers are with the flapper removed.

that is about what i get too on my 94 K75S.  consistently get 48-50mpg.   mostly sporty backroads riding with a little slab to get to them.  on a track day though...got 21mpg for some reason...;-)

the more modern bike, K1300S, gets 46-48mpg.

[Laitch]

that is about what i get too on my 94 K75S.  consistently get 48-50mpg.   

Same here on a naked '95.

[rbm]

I'm getting about the same on a naked K75, even having fitted K1100 injectors with higher flow rate.

[White Dog]

I class myself as a "conservative rider."  No excessive speed, no jack-rabbit starts, so I can't understand why my MPG is low, as compared to youse guys.  Then, there is the issue with the low fuel idiot light.  I do not have a gas gauge--it's just a plain ole K75 with OEM side bags.  Oh, yeah, I added a small, aftermarket trunk, but my body blocks the wind going to it, so I've got to look some other places.  Incidentally, my R1100RT gets much better MPG than the K75 and I do ride the R1100 fairly aggressively.


There is also the chance that my perception of gas volume remaining in my tank is in error.  Can anyone tell me in inches how far up the RH side of the tank one gallon of gas would measure?  (With bike on center stand)


Four gallons is probably tops at a fill up with mileage varying from 145-160.