The Honda PCX / Forza / ADV150 / SH Forums

I always fill up with premium fuel, 91 octane. My reasoning is that the Forza is 10.5to1 compression ratio meaning that it calls for a higher quality fuel. The owners manual states use 86 octane or higher. My old car, a 1970 Oldsmobile Ninety-Eight had a 10.25to1 compression ration on a 455 Rocket engine. It called for 91 octane premium fuel only. Don't cheap out on a couple gallons to save a few dimes, get the best you have available. Safe riding!

I have been pondering this here in the UK too. Standard is 95 octane where I live, and premium at Texaco is 97, and at Shell with their V-Power fuel is 98 octane. The manual I have says 91 is fine. Although given it's a 125cc bike, I very much doubt putting 98 octane in will see it performing side by side a Yamaha R6!

Still I am using Texaco's premium fuel, as it's only 3 pence more per litre.

The only reason I'd see for using premium fuel if the manual calls for regular would be that premium in my area is typically ethanol-free.

DrewJW wrote:I have been pondering this here in the UK too. Standard is 95 octane where I live, and premium at Texaco is 97, and at Shell with their V-Power fuel is 98 octane. The manual I have says 91 is fine. Although given it's a 125cc bike, I very much doubt putting 98 octane in will see it performing side by side a Yamaha R6!

Still I am using Texaco's premium fuel, as it's only 3 pence more per litre.

Must be a difference in measuring methods between the US and everywhere else. Here, 98 octane is $10 per gallon race fuel. We are 87/89/91. With fake gas mixed in.

I always get a laugh out of the talking points of regular vs premium fuels. If you would just google OCTANE and see why it is in gasoline you would realize that these talks are not at all needed.

I use premium in the Forza (and in my 64 Rambler and 2000 Saab) because it doesn't contain ethanol...or so the sticker on the pump claims. Probably the Forza and Saab would be okay with 10% ethanol but not sure about the old Rambler. It irrational I know, but I feel I'm being "nice" to the vehicles by not using ethanol blended fuel!

The PCX is designed to run on a 10% ethanol mix, there's absolutely no reason whatsoever to use anything other than what the manual states.

Got to agree with gn2 on this one

You're wasting your money by putting anything more than what your owners manual recommends. Most bikes only need regular unleaded gas. Even the CBR 600RR and 1000RR only require regular.

My 2012 Mazda 3 Skyactiv has a 12:1 compression ratio and only requires regular. Even the newer ones with an even higher 13:1 compression ratio requires regular. The overseas Skyactiv engines have 14:1 compression ratio and those require premium fuel. With fuel injection and all that fun stuff, the manufacturers have become very good at preventing detonation at high compression and lower octane.

This is the way I understand fuel
ethanol lessons detonation
but nasty on carbureted engines
fuel injection was a game changer

A postscript
lead was used as an anti knock compound not too many years ago
enjoy your regular gas fuel injected technology

We use reguler in our pcx 150s but if we find a station that sells regular without the ethanol we stop and fill up. There are stations outside of Atlanta that do carry regular without ethanol, but they are waaay out in the country. That makes riding the back roads good in two ways, the scenery and the better gas. The way our cars AND our scooters have been running lately, I think they must have boosted the amount of ethanol in the gas. They sputter and even shut off at a light sometimes. They don't accelerate like they should, and sometimes they hesitate when I open the throttle. All this straightens out if I add Seafoam OR if I find good gas. The problems don't happen all the time, just on occasions but then it seems to be at all the local stations.

relic wrote:A postscript
lead was used as an anti knock compound not too many years ago
enjoy your regular gas fuel injected technology

It was also "apparently" used as an upper cylinder lubricant and to stop valve seat wear. Both pretty much unfounded.

Still we have ethanol and synthetic oil to angst over.....

I've got the option of filling my tyres with Nitrogen. It's only a few cents more should I go for it?

you you wrote:

relic wrote:A postscript
lead was used as an anti knock compound not too many years ago
enjoy your regular gas fuel injected technology

It was also "apparently" used as an upper cylinder lubricant and to stop valve seat wear. Both pretty much unfounded.

Still we have ethanol and synthetic oil to angst over.....

I've got the option of filling my tyres with Nitrogen. It's only a few cents more should I go for it?

Sure go for it! Why not add a 9v battery and try to claim it as a hybrid while your at it?

you you wrote:I've got the option of filling my tyres with Nitrogen. It's only a few cents more should I go for it?

Stick a hose up your arse and fill them with methane.

gn2 wrote:

you you wrote:I've got the option of filling my tyres with Nitrogen. It's only a few cents more should I go for it?

Stick a hose up your arse and fill them with methane.

Wouldn't work for me. I'm a virgin in that area.

Still it's a top tip. Nothing beats experience.

Mel46 wrote:We use reguler in our pcx 150s but if we find a station that sells regular without the ethanol we stop and fill up. There are stations outside of Atlanta that do carry regular without ethanol, but they are waaay out in the country. That makes riding the back roads good in two ways, the scenery and the better gas. The way our cars AND our scooters have been running lately, I think they must have boosted the amount of ethanol in the gas. They sputter and even shut off at a light sometimes. They don't accelerate like they should, and sometimes they hesitate when I open the throttle. All this straightens out if I add Seafoam OR if I find good gas. The problems don't happen all the time, just on occasions but then it seems to be at all the local stations.

Marine fuel stations will have ethanol free gasoline, as many boats cannot take ethanol.

Around here, I can get Shell and Costco 91 octane and Chevron 94 octane ethanol free. But none of my current vehicles need premium so I don't bother. My old Toyota Sienna required 87 but recommended 91 as 87 made it lose 10 HP, so that's what I fed it.

My dad's old PGO 49cc scooter had a larger sticker next to the gas cap that said "Premium fuel only" which I found interesting.

gn2 wrote:The PCX is designed to run on a 10% ethanol mix, there's absolutely no reason whatsoever to use anything other than what the manual states.

I own a Forza, I didnt know the PCX was designed to have a 10% ethanol mixed fuel or any engine for that matter. I also use 91 because it doesn't contain ethanol, around my area in Wyoming. I always thought ethanol was added to help fuel lines to not freeze in the winter time. How many people out there are in the south? Do you guys see ethanol added commonly? I would assume that ethanol being added to fuel is a geographical thing. In the mean time I'll continue to avoid putting ethanol mixed fuel in my machine because I'm not going to ride it in the winter anyway.

All vehicles manufactured for use in the EU must be capable of running on a 10% ethanol mix.
The Forza 300 is sold in the EU.
Ethanol is added for political reasons not because of any merits it may or may not have.

gn2 wrote: Ethanol is added for political reasons

This.