There is a long topic on gas octane for the ZX14 on here (old thread). I thought I would bring it up again for discussion. Mother Kaw recommends 91 or greater for the 14R but I personally have always run top tier (Shell) 89 octane gas in all my ZX14's on the street. High octane pump gas contains no more energy (BTU's) than 87 octane pump gas. The difference is that it burns slower to prevent pre-ignition spark knock. In the motors I have built and run the 87 & 89 octane pump fuel burns cleaner and there are less deposits left in the combustion chambers. I started running the lower octane pump gas after talking to Rob Muzzy at Daytona. He had a piston kit for my ZX12 that was 13.5/1 and he told me to run 89 octane with it. Ran like stink and when I later built my first ZX14 (2006) we used a thinner head gasket and milled the head for 13.5/1 compression. We ran 89 octane pump on the street and MR9 which is a fairly low octane (87 octane) oxygenated race fuel on the track. The 2006 was running a Brocks exhaust and mapping on the Power Commander. Brocks instructions were for 89 octane pump for the street with a separate map for the MR9.

Interesting to see what you guys are running. Like I said I have been running 89 pump gas on the street since my ZX-12 days back in the early 2000's.

* Last updated by: jstewart on 11/8/2020 @ 9:07 AM *

I use 92 or 93 whatever the premium gas is. I used midgrade when the bike was new and it made the exhaust pop more. That was the only difference I could tell. Midgrade also has ethanol.

* Last updated by: Rook on 11/9/2020 @ 4:52 AM *

Everything is ethanol blended here Rook. If I remember you are in Canada and we use different rating methods for octane rating on pump gas. By the way is the Canadian border still closed to US tourists. I was planning on a vacation on the trans Canada railway and then the Covic hit and that shut that down.

NO in NW WI and Upper Michigan I'm close to the Canadian border but I live in the US. Our Premium is non ethanol. I wouldn't mid visiting Canada either.

For what it is worth Brock Davidson recommends using 89 octane. According to his R&D this is the best octane to use either fully stock or with his pipes and map. For my 2 cents I give my trust to Brock totally ... He has videos on the matter if interested.

I use regular 87 crap, whatever is cheapest. Except Shell. I will not run that in
any of my vehicles.

Mad

I use regular 87 crap, whatever is cheapest. Except Shell. I will not run that in
any of my vehicles.

jst, you may recall on the old thread: I bought a scope. Pulled the plugs to take a comp test and check cylinder walls for lines... incredible shrinking stone scribing its mark, or debris in the oil. I also saw the V mark used to set the piston in the lathe and all that. Sister moved and it had a slightly steep hill up to her house. Ran the cheap costco. Maybe the first time going there on the bike, too high a gear, too open a throttle and it pinged like a mother till I backed off hearing it.

Brought the scope out and checked another time, if not going home that day. Right where the end of that spark plug meets that V, it now looked the crater. No longer a V, but tiny welded balls of aluminum blown out of that area on the knocking.

Never changed to 91, just knew not to lug it/open the throttle up with that combo. However, back in the day yanking those throttle bodies a few times, I could see carbon buildup on the intake. I then switched to, cough, shell. Pulled the bodies or checked thru the service door, don't remember, but do recall how, cough, clean those valves were.

Oh look, chicken alfredo!

Yep Hub, Maddevil must have had a bad experience with Shell gas. I had a friend who got a tank of Shell at a rural station that had water in it. Me I have never had that experience and that wasn't Shells fault. Shell is a top tier gas and I use it wherever it is available or Chevron. Both of them use Techron additive which is some of the best stuff on the market for keeping your valves and combustion chambers clean. As far as spark knock from lugging the motor it has happened to most of us at one time or another.

I could be wrong about Shell now, but in the past, virtually every vehicle I ran Shell in pinged like a mother. Add in I was overhauling the carbs on a friend's bike and every rubber seal was destroyed. And they all smelled like sulfur when running. Ill pass.

Mad

Kinda like Buttwipers beer. Yeah, it's beer, but really shitty beer.

Mad

Ive been researching the octane debate across the net and there seems to be an even split on whether or not it's safe to run fuel that's lower rated than what's recommended my the manufacturer, and if there's any benefit in doing so. Since the temperature cooled down to the lower 80's I decided it'll be safe to fill up with Shell 89 octane to see if there's a difference from 93 octane that I've always used.

My first impressions are that I can definitely tell a positive difference in the way it pulls....meaning my butt dyno registered that the engine runs stronger on 89 octane with no pinging. I've always used the octane rating recommended by any vehicle's recommendation, but for the time being I'm going to stick with Shell 89 octane unless of course I encounter issues.

I would love to know how our fuels compare, we have the following here (but our octane ratings don't seem compatible):

91 - common unleaded for low compression shopping cars and postie bikes
E10 - 10% ethanol for 94 octane rating - govermnent attempt at renewable fuel for the masses but many "compatible" vehicles suffered failures from this stuff so people just don't like it. My son uses it in his Z1000 but I won't put it in my car's.
95 - lower end premium (I use this stuff)
98 - higher end premium fuel (many people use this in their every day stock cars because it's "better" but they have no idea why they are paying $2.50 per litre when they don't need to. Must have for high compression or turbo.
E85 - 85% ethanol for 100-105 octane - this stuff is hard to find and you need a heavily modified fuel system to handle the volume required, blown and turbo modified cars use this and often have a whole separate system for e85 then use normal gas for street driving
Avgas - I used to get this for my car as I lived near a small airport - around 100 octane
We have VP fuels here but stupidly expensive, I am certain no street rider or driver uses this stuff and many race vehicles don't even use it because it's just not worth it
Methanol - relic of the blown alcohol drag cars - very painful on the street, worse than e85, guys often have a chase car with drums of fuel in a trailer when these guys go for a cruise.

Apparently the US 89 is similar to our 95 but I can't confirm that.

For comparison these are the prices at my local petrol stations today:

91 is between 1.64 and 2.14 (yes you can save 50c per litre by driving half a km)
95 is 1.81 to 2.26
98 is 1.89 to 2.34
E85 is 1.95 but the nearest outlet is 17km away
Diesel (regular grade just for comparison) is 2.25 to 2.38

I had trouble finding a price for MR12, the best I found was au$306 for 19L (Yes $16 per litre)...

:)

Globally octane rating calculations can vary, I believe in most cases US octane ratings "show" a lower number than for example Europe. For example, 92 octane in US may be 98 in UK. I'm not trying to be specific here and don't care if 92 isn't 98, just example for illustrating the point (it may or may not be accurate). Exact differences can be found searching.

I use E0 90 (US, considered low premium here) and had my bike stored for 4 years with no stabilizers. Gas smelled a bit, but she fired up like it had just been started the day before. Ethanol gas is fine and usually boost octane I just prefer to run ethanol free in my vehicles and power equipment (definitely power equipment, avoids so many problems).

I just fueled up my bike with 89 for the first time in its life. I went to the pump and there was a 50 Cent premium price on premium. I remember when premium was only 20 cents higher than regular. So anyways I read this post and gave it a whirl. On the ride home I noticed zero difference. I am not a hard rider. If I don't notice any major differences, I will probably keep on buying mid grade. I've always thought mid grade was ridiculous because there's really no vehicles designed for it but why not :-) thank you all for sharing your wisdom.

I’ve been running it exclusively since my last post and so far I haven’t experienced any issues, even running it in 105-110 F days.

Yeah, you're not really going to notice a difference. If you were a skilled 1/4 miler, you might notice a difference between some E10 93 and 89, maybe a tenth or 2 (maybe chrly could do some testing for us?). The dyno would probably notice, 4 hp. That's all insignificant as far as real world operation, the concept of "feeling" 189 vs 193 hp is ridiculous.

If someone gets and runs 89 or 90 (like me) and notices a difference it's probably more they just go bad gas than "93 pulls WAY harder!"

I stopped last week at my local Shell Station. The sign said $3.39 for unleaded, so usually $.50 more for the good stuff, not this time.
$1.50 more.
I remember in good old days that Premium Leaded was $.04 higher than $.25 Regular Gas. I rode a motorcycle most of the time because my Car did not AC. I only made $544 a month as an E-5 in the Army (1972).

I always run Exon Mobile premium 93 from day one on my 2022 ZX14R. My 2013 Concours 14 I could feel the difference from 87 to 93. But I drive my bikes hard.

Here's some interesting facts about octane.
87 or E85 produce more power than high octane fuel. The problem with 87 is detonation. High octane gas like 93 has additives that slow the burn down to prevent this. I've never heard any detonation or pinging in my bikes but I don't lug them either. So I always run 87 and have for thousands of miles.

Mad