Regular, Mid Grade, or Premium Gas?

[jdub0813]

I have read mix reviews on whether to run premium or not so my first fill up was mid grade.  Wondering what everyone else uses?

[CROSSBOLT]

Kymco engines are designed to run on 87 octane gasoline in this country. 85 octane above 3000 feet elevation. Higher octane than manufacturer recommends is a waste of money and returns lower performance.

Karl

[jdub0813]

But I also read it doesn't affect it, so might be a waste of money, which isn't too much more say you spend 25 cents more a gallon so $2 every fillup?  But you get longer shelf life, meaning if you're not riding every day the, regular gas loses it's integrity over time.

[CROSSBOLT]

Use whatever grade you want. For what ever reason. I do not really care. Why ask the question if you are going to argue with the answers? This octane discussion was finalized in the 1920's by engineers and technicians developing what turned out to be some of the most highly refined aircraft engines in the world. Things have not changed since. What has changed is electronics which allow some enormous comression ratios on some surprisingly low octane fuel. Pilot training back when we had available 3 or 4 grades of avgas would tell us we COULD use gas of the next grade UP if our normal grade was not available. But NEVER use any grade lower. We were cautioned to expect LESS  PERFORMANCE using a grade higher because of the slower burning rate.

Karl

[jdub0813]

Wasn't an argument, I  asked for people's opinion and I thank you for yours. I just mentioned that higher octane has higher shelf life so maybe a reason to use that?  I don't know, it's up for debate, which is the reason of my post.

[Mr. Paul]

If the owners manual calls for 87 octane, that is what I would use. Karl is right, higher octane gas has a slower burn rate that decreases pre-detonation. (pinging). This slower burn rate decreases the engines performance. Higher octane has no other benefit and is unnecessary unless it is called for. As far as storing goes, I believe that is a separate issue best resolved by using non-ethanol fuel and perhaps a little SeaFoam.  In short, go with 87 octane, ideally non-ethanol.

[CROSSBOLT]

Absolutely, Mr. Paul! Seafoam, Sta-bil and such products lot cheaper than higher octane. Separate topic, definitely.

Karl

[jdub0813]

Okay, and I do use Seafoam periodically in all my vehicles.  Guess I will just stick to regular and keep using Seafoam periodically.

[CROSSBOLT]

You will NEVER have any problems with  any Kymco because of 87 octane fuel. Now, you may have a raft of problems caused by marginal battery/starting systems, stuck fuel vent valves or weird electrical gremlins!

Karl

[randyo]

when I drive 450i to the gas station it gets regular 87, if I add some from my spare gas container at home, it gets premium, my spare container (holds 7+ gallons) is fuel for a myriad of small power equipment, motorcycles, cars &  trucks, some of which use premium

[Mr. Paul]

Okay, and I do use Seafoam periodically in all my vehicles.  Guess I will just stick to regular and keep using Seafoam periodically.

Good plan! 

[stuo]

"...higher octane has higher shelf life...." Says who?  A higher octane rating is strictly a measure of the fuel's pre-detonation ability, which high compression engines require or they will knock and possibly self-destruct under acceleration. The fact that 91octane is called "premium" and costs more doesn't make it better, more powerful, cleaner, etc. I wonder if the higher price for 91 is nothing more then Big Oil gouging us, like they did for a while when diesel was more expensive then gasoline. I know people, even mechanics, who believe 91 is better gas then 87.   "Hell, it's got a bigger number and costs more so it must be better, right?" Duh.

[jdub0813]

Many sites and mechanics... but like you said, who really knows as mechanics seem to be 50/50 about premium vs regular.  So I guess really it boils down to what I choose to do and I am just going to run regular with occasional seafoam from time to time.  I have always ran premium in my motorcycles and never once had a problem, so let's just test the Kymco with regular and see if I wasted money the entire time with my bikes.

[airshot]

Many sites and mechanics... but like you said, who really knows as mechanics seem to be 50/50 about premium vs regular.  So I guess really it boils down to what I choose to do and I am just going to run regular with occasional seafoam from time to time.  I have always ran premium in my motorcycles and never once had a problem, so let's just test the Kymco with regular and see if I wasted money the entire time with my bikes.

Not a waste if your mfgr recommended a higher octane fuel. My older atv's all called for premium 91 octane fuel but the 450i just says regular fuel. I have used both 87 and 89 octane in it and see no difference.

[stuo]

"Not a waste if your mfgr recommended a higher octane fuel. My older atv's all called for premium 91 octane fuel but the 450i just says regular fuel. I have used both 87 and 89 octane in it and see no difference."

The "difference" is the money you wasted buying higher octane for no valid reason.