Premium vs. Regular Gas

[Mrs.Spaceman]

I know this has already been discussed, but I haven't really been satisfied with the answers... I need to find real documentation on what RQ really means.

I took the Roughhouse it in to have a bigger jet put on after deciding the 85 wasn't cutting it. Well, a few days later the next time I took it out, it died on me at a stop sign, and my low end was very unstable. So, I took it back in. The mechanic re-adjusted everything, and it was good to go. Next fill-up, I put regular in again, like always. Died again. Took it back AGAIN. While disassembling my seat, I noticed it says right there to use gas with RQ of 92 octane or higher. DOH! So, what happened was when I took it in the first time, I was low on gas. The mechanic put a little gas in it for me, and had put premium in. So, it was tuned to be running on premium. I filled it up next time I rode it with regular, not knowing he had put premium in the last time. And the cycle repeated.

I am confused. I didn't think I needed higher-octane gas unless I have a high-compression engine. Is the RQ 92 under the seat equivalent to RON in (R+M)/2? If so, then using 87 regular should be just fine. I'm trying to find some real documentation, not just what people say on a forum (no offense) to take back the mechanic to tell him I think he is wrong. I don't mind paying extra for premium since it adds fractions of pennies on the mile, but I don't want the engine running too hot either.

Any experts out there?

[ScootLemont]

From Wikipedia
The octane rating is a measure of the resistance of gasoline and other fuels to autoignition in spark-ignition internal combustion engines. High-performance engines typically have higher compression ratios and are therefore more prone to engine knocking, so they require higher octane fuel. A lower-performance engine will not generally perform better with high-octane fuel, since the compression ratio is fixed by the engine design.

so... if your engine was designed & tuned to run at high compression, high octane gas should keep it from knocking. But it is not built or designed as a high compression 2 cycle engine (some dirt bikes & racing snowmobiles are)
Ask your mechanic if your scooter engine is a high compression engine.
(its not)

I know thats not the documentation you are after -

that all being said - mine runs fine on regular gas
if yours runs better on 92, it is only costing you about 1/10th of a cent per mile.

[Mrs.Spaceman]

Yeah, I saw that article. Thanks though! What I am really looking for is what that stupid "RQ" means. It doesn't really matter to me what I use, I just don't want to be harming the engine. I'm sure it will be fine if everything is adjusted properly and running smoothly. I actually am getting better mileage now, but that is more likely because it is now tuned properly.

My brother swears I need to be putting premium in. He told me I should go to the airport and get some low-lead 100 octane gas. I doubt that is a good idea.

Love your avatar by the way

[ScootLemont]

saw that pic on a website & thought that HAD to be my avatar - simpsons rock

anyway... has anyone thought to email genuine about the RQ 92 number?

info (@) genuinescooters.com

[brimstone]

just my .02 but i've heard that 2 strokes don't generally get value from premium gas like a 4 stroke does. my friend who has a honda metro runs premium like every 3rd tank and swears he can feel the difference. me, not so much, i just honk and wave as i pass him on my 110. hehehe

[ScootLemont]

I dont know what difference he can be feeling - more octane is NOT more power or energy - it just means it will NOT explode (knock) at lower pressure or temp.
In short, it is harder to ignite higher octane gas.
Hi perf. cars spec hi octane gas (corvettes, porche, etc) because their engines are designed to run at a higher compression & thats how the generate more HP - if they ran lower octane gas, they might knock - but the power is in the engine design NOT the gas.

There is little difference in energy content of regular versus premium gasoline. They both contain about 111,400 British Thermal Units of energy per gallon.

http://www.consumerenergycenter.org/tra ... emium.html

most high octane gas DOES have more additives & detergents - that makes me a little nervous about using it in a 2 cycle -

But... back on topic - what genuine owners need to know is what "RQ 92" really means - if it is the pacific rim octane rating then US 87 octane gas is actually a higher octane.

[ScootLemont]

So, what happened was when I took it in the first time, I was low on gas. The mechanic put a little gas in it for me, and had put premium in. So, it was tuned to be running on premium.

Low on gas? - how much is low? - if you had a quart left & you get 80mpg, your guy would have had to ride it 20 miles to burn through your regular gas - if he added premium to your regular & it was the same amount - your mixed gas would have had an octane between the two - not the high octane of the "premium" gas.

[Mrs.Spaceman]

It doesn't get 80 mpg when flooring it up and down the street repeatedly, although it would be pretty sweet if it did. The mechanic spends A LOT of time with it, making sure it's perfect. I probably had about 10 miles worth of gas left if I was riding it normally. I normally don't let it get that low. I'm usually putting in .6 or .7 gallons whenever I fill up. The mixture would've been at least 80% premium after he filled it up. It has been fine ever since I got it back and found out that's most likely what the problem was. I don't know if it really matters all that much WHAT you use, as long as it's not crappy gas, everything is properly tuned, and you are consistent with what you put in. Of course filling up with 110 octane racing fuel would probably be a bad idea...

[ScootLemont]

just curious... when you bought your regular gas & had trouble... was it from a national chain gas station?
& since you had the trouble a couple times, are you buying gas from the same place?
or did it happen with regular gas from more than one station?
I think it might be possible that you you might be getting some bad gas
maybe?

[Muggs]

I only use Shell 92. My spark plug after 400 miles look new. My mechanic has a collection of spark plugs and he showed me cheaper gas from other gas stations (you know who they are). The plugs were pitted and nasty. He had one with 1000 miles on it that only Shell 92 was used. Clean as mine was after 400.
I've never put a gallon at a time...so even with 4.24 cent gas, I only put in 3.80 cents. My empty is not empty.
I'm getting close to 90-100 miles a gallon. Don't know if 92oct makes the difference but......
Muggs

[Mrs.Spaceman]

I almost always fill up at Shell. That is where I got gas from when it was dying on me. It has been great with the 93 V-Power (or whatever it's called), so I'm gonna stick with it unless I notice any problems. It is very likely my spark plug was f-ed from all the tuning. I didn't even think about that. I have a new plug in now. The jet has been swapped out 4 times (I think) in the past month. Started with a 90 when the exhaust was put on, went down to an 85, got the air filter and went back to a 90, and am now using a 95. Didn't think I'd need to go that big, but it's workin' pretty darn well. I have a little "second boost" in acceleration between 40-50+ mph (indicated) that I didn't have before. I need to find someone my weight to jump on my husband's Roughhouse (which still isn't sold) and ride next to me. It would be pretty cool to have a video of stock vs. upgraded.

[Budders]

It is like driving a car that has a lot of upgrades on it. If you buy something that has high quality parts on it it is going to require high octane gas I had a Subaru WRX that if I were to put regular in that thing I would have been surprised if it would have turned over. It required a cleaner oxygene to fuel ration so that it could run at a higher temperature. same thing with your scooter if you are putting upgrades on it then it is probably running hotter and lower grade gas doesnt burn nearly as well at high temps as high grade gas does. So if you want the performance that you are probably looking for out of your upgrades (I am sure that you are) you are going to need to put gas in that was made for those parts

[ScootLemont]

I dont want to start this all up again but....

high quality parts do not require high octane gas
high compression engines do (like in your Subaru)

spark plug look better with 92 octane? Sure - nothing to do with the octane - the "premium" grade gas have more detergents in them

Premium gas is not "better" gas - all US gas meets the same specs & burns at the same temp. "Premium" gas has a higher octane so it will not ignite too early - "premium" is more difficult to burn (needs higher pressure)

"Premium" gas contains no more energy than regular gas

Octane rating is NOT energy - it is the resistance to knocking.

"racing" fuel is very high octane because racing cars have very high compression engines. Racing fuel does NOT make your car go faster.

If you scooter does not knock or ping with 87 octane gas, the only advantage to using "premium" would be for the slightly higher levels of detergents.
If that makes it worth it to you, great.

As for a specific brand of gas....
for those who buy shell brand...
Mrs.Spaceman- I will bet 50 cents that your shell gas station is selling gas made at the BP facility in Whiting - Shell does not ship gas from Calif. Texas or Washington to Indiana - they would not be able to sell it for the same price as the BP stations.
I am sure the gas that your local Shell station is selling meets Shell's specs. & MIGHT even be a shell specific blend, but it aint coming from Shell refineries.
I live a few miles from a Citgo refinery - their tanker filling station is right on the main road - I see other companies trucks filling up there all the time.

Here is a fun fact - Ethanol raises a gasoline's octane but has LESS energy than straight gasoline. Most E85 has an octane OVER 100 but E85 has about 20% less energy than "straight" gas.

so... if you want to use higher octane gas fine with me
if your car requires it because it has a high compression engine - you better
but "premium" is just a marketing name for high octane gas - it has no more energy than any other octane gas & will give your scooter no more power or speed.

again... if you want to use it, fine with me - I just wanted to explain it in a little more detail.

[ScootLemont]

If you buy something that has high quality parts on it it is going to require high octane gas

The Subaru WRX STI uses:
2.5-liter DOHC intercooled, turbocharged 4-cylinder horizontally opposed SUBARU BOXER engine and requires 91 octane

The Subaru imbreza uses a 4 cylinder horizontally opposed SUBARU BOXER engine and requires 87 octane

The wrx engine is turbocharged & is tuned for much higher compression - with out the high octane it would knock.

I doubt that subaru is putting in low quality parts to their standard version of that engine -

BTW - I LOVE my Subaru & will buy another one to replace the one I have, if the thing ever stops running - & I dont think it will.

[Mrs.Spaceman]

I amost bought a WRX a few years ago but instead went for something more "practical" and got a Nissan Maxima. It requires premium as well. I accidentally put regular in once, and it ran like crap. I didn't really notice any knocking, but the decrease in performance was definitely noticable.

ScootLemont-You are probably right about Shell getting their gas from Whiting. Why then, if it is so close, does it cost more here than southern Indiana? That's a rhetorical question

[ScootLemont]

any modern engine designed to run on higher octane will "de-tune" itself when the engine's computer figures out you are running lower octane gas - when that happens you will, most likely, have less power - but not because of the gas, it is because the engine is changing the fuel / air mix, timing, etc to prevent the lower octane from detonating too soon

[Mrs.Spaceman]

I remember when I didn't know any better and used to put premium and 2 things of octane boost in my old Civic. I admit, it was a ricer. I traded the thing in before I blew it up. Of course driving down 80/94 ad 110 mph all the time on my way home from church probably had something to do with it... or the time it was driven 125 most of the way home from Colorado Springs... Ah, the good old days!

Anyway, thanks for all the input! It's good to hear differing opinions.

[ScootLemont]

Here is a fun fact - Ethanol raises a gasoline's octane but has LESS energy than straight gasoline. Most E85 has an octane OVER 100 but E85 has about 20% less energy than "straight" gas.

and a follow up - they sell E85 (15% gas & 85% ethanol) and not E100 because no normal cars would be able to run the stuff - the octane of most ethanol is between 113 & 120 - because of the high octane, it is so hard to detonate, that most cars do not have compression high enough to run on it. (and it would get you about 30% wors MPG because it has less energy)

[sugonaut]

110 mph all the time on my way home from church

That is why God created Saturday night... to make sure I'm just getting to bed by the time you head off to church.

[Mrs.Spaceman]

Haha! I just had one of those nights this weekend. I don't anymore, but I was getting paid to go I was the organist. How else was I supposed to afford the gas to drive 100 mph all the time? Hehe. My mom would kill me if she was reading this.

[sugonaut]

My mom would kill me if she was reading this.

Mine too.

Nice paint, BTW.

[Evans Performance]

listen to ScootLemont. he is pointing you in the right direction for octane.

in a turbo car it will run great on 87 octane(when not boosting) cause turbo cars have less compression. once you get boost pressure you will get knock and thats why turbo cars require higher octane. no matter how many expensive parts you throw on a car, it wont change the needed octane. if you raise the boost enough, then you would need a higher octane.

E85 is junk and dont let anyone ever tell you different. it does work pretty well in racecars due to the higher octane but it takes twice as much e85 to make the same hp as 93 octane unleaded. e85 is also bad for your fuel system. it is basically alcohol. alcohol is water soluble. water in your gas causes corrosion.

race gas(110 octane) is bad for a "stock" rattler due to the lead content. race gas has lead in it and it will clog the catalytic converter. its fine if you have an aftermarket pipe. over some time it will clog the spark plug, but on a non turbo or high compression engine thats not much of an issue. also, rattlers have very low compression and would not benefit from higher than 87 octane. Mrs. Spaceman, you would get more power by having your scooter tuned for 87 octane.

just to add a small amount of credibility to what im saying, i build racecars as a side business during my free time, my day job is an airplane mechanic and i also have built 2-stroke 49cc pocketbikes for racing that will smoke a rattler 110.

[ScootLemont]

Evans Performance:
are all 2 strokes low compression?
That is what I was told... but not by a guy that would know first hand... so I didnt want to throw that out there.

[Ray Knobs]

Racing snowmobile 440cc engines are high comp and must run on race gas or be converted be changing out the domes in the cylinders to low comp so the can run pump gas.

[ScootLemont]

Racing snowmobile 440cc engines are high comp and must run on race gas or be converted be changing out the domes in the cylinders to low comp so the can run pump gas.

but my 82 John Deere Trail Fire 440 (& my two newer Polaris trail sleds) are low compression right? - is it just the "racing" sleds that are high compression?

[Evans Performance]

normally any 2 stroke that you buy will have low compression. if you buy a high performance snowmobile then it may be high compression. i dont mess with them in FL. lol

there is no reason a 2 stroke cant be high compression though. i think the rattler comes stock around 8:1 but my pocket bike has 12:1. its all in the tuning. if you get detonation you can go a step colder on the spark plug to help or higher octane gas, reduce timing a little, ect.

[nissanman]

I'll have to do some looking around, but PGO has some 6.5:1 compression 2strokes they produce too. The BuckTen might not even be running 8:1! Before they started importing them I know I read that the 110 Naked had that super low compression. Theory is so that they'll run on just about any crap gas in the world.

[Ray Knobs]

but my 82 John Deere Trail Fire 440 (& my two newer Polaris trail sleds) are low compression right? - is it just the "racing" sleds that are high compression?

Yeah, back when you could buy consumer model 440's they were low compressions. Race sleds are special order from the factory, you have to fill out an application to get a new one or find a dealer that bought some on spec. Usually people picked up used ones and trail convert them because they think they are too hardcore for normal sleds.

[Evans Performance]

i knew the rattler had really low compression. i remember reading it somewhere but i didnt know it was as low as 6.5:1. i cant belive it runs at all. lol

i just looked at the service manual and the 50cc is 6.8:1 and the 110cc is 6.6:1. i am pretty interested in upping my compression a few points and see what i get.

[ScootLemont]

i just looked at the service manual and the 50cc is 6.8:1 and the 110cc is 6.6:1. i am pretty interested in upping my compression a few points and see what i get.

cool - so now we know for sure that the stock rattlers have low compression engines -
& with a compression of 6.8:1 I am surprised they will run on 92 octane at all (kidding)

[wparente]

Engines are designed to run on a specific octane rating. If you put premium gas in an engine designed for regular the flame front (explosion) will develop later after top dead center on the piston, thus reducing horsepower and performance. This goes for scooters as well as cars! In two cycle engines just increasing compression may not necessarily improve horsepower; it could require reporting to achieve any improvements which will more than likely reduce mileage.

[Mrs.Spaceman]

That's where the confusion came in, at least for me. It says to use gas with RQ 92. No one seems to know for sure what that "RQ" means.

[ScootLemont]

That's where the confusion came in, at least for me. It says to use gas with RQ 92. No one seems to know for sure what that "RQ" means.

I just emailed Genuine - I will let everyone know what they say.

[wparente]

As stated in Wikipedia
In most countries (including all of Europe and Asia) the "headline" octane rating, shown on the pump, is the RON, but in the United States, Canada and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 8 to 10 point difference noted above, the octane shown in the United States is 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "regular" gasoline in the US and Canada, is 91-92 in Europe. However most European pumps deliver 95 (RON) as "regular", equivalent to 90-91 US (R+M)/2, and some even deliver 98 (RON) or 100 (RON)

[Mrs.Spaceman]

That helps I don't know why I couldn't find that on Wikipedia... must've not been searching for the right thing.

[ScootLemont]

I have read that... but what I would like to see is something that says what RQ means... is that the pacific rim notation for the RON number?
If so then we can finally put this to bed

I do find RQ on MSD sheets for gas & other stuff - there it stands for Reportable Quantity - the it seems to be a US term for how much of the stuff you have to spill before you have to report it

[wparente]

You don't suppose the translator made an error. That would seem so unlikely considering how the rest of the manual turned out.

[ScootLemont]

thats what I have been thinking...

[Evans Performance]

yea, i have a feeling the RQ is the same as RON

[ScootLemont]

I would just like to know for sure so we can put this to bed once & for all

IMO - this has been the best gas thread on MB - lots of really good info

[Mrs.Spaceman]

Hopefully you hear something back from Genuine, and they know what RQ is. The way everything else is proof-read, you'd almost think they don't even look at anything before it's sent out.

[ScootLemont]

well... never heard from genuine about it