The Honda PCX / Forza / ADV150 / SH Forums

Can I run premium gas in my PCX150? Or would it do more worse than good?

not necessary and some here will say can do harm to the little engine over long term use.

homie wrote:not necessary and some here will say can do harm to the little engine over long term use.

So safe to say stick with 87 octane?

Stick with what the owner manual says = 87 (US)

Filling with premium does nothing except empty your bank account a little bit more than "low grade".

I see quite an improvement in mpg running shell v power nitro + 98 octane uk

Tom192 wrote:I see quite an improvement in mpg running shell v power nitro + 98 octane uk

Its all in your head.

I only use standard unleaded petrol (cheapest) and have some of the highest mpg figures in Fuelly - like with many things in life, more expensive does not mean better.

I tried 98 octane not long after I got my bike to compare it to 95. It made no difference in my opinion.

Today we went for a long ride, including some freeway time. We had filled up the day before at a remote gas station...we went for a long ride yesterday also. When we started out this morning the bikes were spitting and sputtering, and almost shut off several times. The station we had filled up at only had gas that had 10% ethanol in it. Our ride today was uneventful but not smooth. Once the gas gauge was finally down at the halfway mark we filled up with medium grade gas. That seemed to dilute the bad gas enough that we regained our smooth running engine and quick acceleration. Other than that, mileage was just about the same, so I am thinking that higher octane probably won't do much more than smooth out a rough running engine. I doubt that it would give you enough of a gas mileage gain to warrant putting high test into your tank each time you fill up.

There is another thread with 15 answers on this subject. Most people say that 87 (USA) is fine.

The owners manual (USA) http://mototh.com/files/honda/PCX150i/H ... al-Eng.pdf
on page 36 it says to use unleaded with a number of 91 (USA) or higher. On page 37 it says to not use gas with more than 10% ethanol.

When i had my scooter at the dealership last week i asked to speak to the mechanic who specializes on PCX. I told him about the forum members saying that 87 (USA) was fine. He said that i should use 91 (USA). He did not give me much explanation.

I asked a car mechanic who said that you can use a lower octane unless you hear pinging (knocking?). Then go up in octane until that sound goes away.

So in the 2015 manual it will instruct to use 91 (premium) or higher?? Im gonna have to look in there tonight.

I realize this isn't a scooter, but for what it's worth...

My car is one that supposedly would derive a benefit from running premium gas. A 2014 VW Jetta with the 1.8L turbo engine.

I've run tanks of 87 and 91 octane through back to back to see if there is a noticeable difference in fuel economy or power.

I've noticed zero difference in either.

The only benefit I can see to running premium fuel is that premium grade is ethanol-free in many cases in my area. Getting rid of the ethanol, in my opinion, would be a much more valid reason to pay more for premium fuel than a hoped for MPG or performance increase.

I know some people are sold on their vehicle running better on premium. There may be a limited number of vehicles or situations where this is the case, but in general I think this perceived improvement is a case of the placebo effect. The placebo effect is well documented in medicine, and I think the same psychological phenomenon exists in other areas, too.

kcpcx wrote:Getting rid of the ethanol, in my opinion, would be a much more valid reason to pay more for premium

Fortunately the PCX (like all Honda road two wheelers) is designed to run on a 10% ethanol mix.
So there's no reason to use premium in a PCX (or Forza)

^ This is true. I try to avoid the ethanol gas for political reasons, not for fear of harming the scoot.

Also, the non ethanol fuel seems to last longer before going stale, without having to add stabilizer. I notice this when using a can to fill my lawn equipment. Takes a while to go through 5 gallons of fuel using a push mower, and the fuel deteriorates before the can is empty if it sits too long. At least it seems to.

Correction to my earlier post. The minimum octane for USA is 86. For UK it is 91. (Thanks to forum member Mel for this information from the owners manual).

In answer to your original question, when i bought my scooter (i am 2nd owner).... the previous owner had used only Premium gas for 2,000 miles. No problems noted.

yak wrote:The minimum octane for USA is 86. For UK it is 91

Reason for this is that octane ratings are not universal which is why its essential to use what the relevant manual says.

gn2 wrote:

Tom192 wrote:I see quite an improvement in mpg running shell v power nitro + 98 octane uk

Its all in your head.

And not in the pocket..

I checked the manual as well. It does say 86+ octane in the US. I think I'll stick with 87 octane and maybe run 89 on occassion to see if it can clean it up a little.

So much miss information in this thread.

YES you can run premium.
NO it will do nothing for your PCX. and potentially lower your MPG's (slightly) due to lower BTU's in the fuel.

Depending on location the % of ethanol is different per grade, up to the national allowed 10% (E-10) Even premium has some % of ethanol. As it is a replacement for mtbf fuel antifreeze.

If you want to run premium fuel for its (claimed) cleaning ability, you would be much better served by a injector cleaner that contains PEA.

As mentioned before, US and European use different ratings. The European use Research Octane Number . We in the USA use (RON+MON)/2. Which is called the Anti-Knock Index (AKI), or Posted Octane Number (PON) 87,89,91,93 are the most common. elevation plays a factor so you may see lower numbers in higher elevation states. An internet search will lead you to how all this is calculated and why.