2014 PCX 150 - speed for best economy

[TheMaverick]

Hi Folks,

I've been doing some longer trips on my PCX (several tanks in a day) and have noted with interest how the range per tank seems to drop off quite dramatically when full throttle into the wind for an extended period of time. So much so that at times I've started to get a little concerned about "am I going to make it to the gas station without running out" (had the last segment flashing on a couple of occasions on the last big trip).

So I'm just wondering if anyone has any "in case of emergency" speeds that would get me the furthest regardless of how long that might take?

Many thanks,

Cheers,

Colin.

[Eiron]

My 2015 seems to get the best fuel economy between 30-35 mph.

[Alibally]

It might be worth keeping a bit of extra fuel in an appropriate container secured under the seat if you have space. At least that way you won't be stuck if you run out.

[TheMaverick]

My 2015 seems to get the best fuel economy between 30-35 mph.

Thanks for that - is that based on the onboard economy meter (which I think the 2015 model has)?

[TheMaverick]

It might be worth keeping a bit of extra fuel in an appropriate container secured under the seat if you have space. At least that way you won't be stuck if you run out.

Unfortunately ... when I'm on a photo mission I usually have the underseat - givi box - and pack maxed out. I have had a lot of success strapping things to the seat behind me ("pillion position"), so I might be able to do that easily enough with a 5l fuel can.

I just find it difficult to judge the economy at times though - that last little twist of the throttle seems to increase consumption quite considerably - and on a long run - at sea level - at full throttle for just about the whole tank - I managed to reduce my range by a full 30km just by being full throttle into the wind compared to the trip in the opposite direction just a few hours before (ie approx 120km to flashing last segment as opposed to 150km on the outward bound leg) (and even that return leg was with some economising).

Would love to have the 2016 model with the bigger tank and better instrumentation ...

[cessna151]

The ABSOLUTE best speed for max range in case of emergency is the minimum speed at which the clutch will stay engaged. That is about 10-15mph. Any speed above that is a compromise between speed and range. The faster you go the lower the range.

[Alibally]

I'm sure there is someone on the forum has talked about using one of these,
http://www.amazon.com/Trangia-Fuel-Bottle/dp/B004RYM1C0

It was strapped to the bike somewhere. It's not that big and would get you out of trouble if you ran out.

[honkerman]

Scooters were developed primarily with the urban commuter in mind. Taking that into account, they are designed to be efficient at speeds native to the concrete jungle. Small displacement touring scooters like the PCX are no exception. While they may be more comfortable over the long haul, they still fall under the same basic laws of physics and fuel economy. For every vehicle there is a fuel efficiency "sweet spot" which will vary depending on gearing, weight, displacement and other factors. An engine running at 2000 RPMs, and doing 55mph in fifth gear is using as much fuel as the same engine running at 2000 RPMs in sixth at 70 mph. It becomes a question of ratios, but after a certain point, you've left that sweet spot and you're no longer running in a fuel efficient manner. A CVT works a bit differently from your standard or traditional automatic transmission as it does not transition from gear to gear, it's a constantly changeable ratio based on the forward and rear pulleys.

This is why, as Cessna151 mentioned, your fuel economy peaks at the speed at which the variator remains engaged the forward pulley. For practical purposes though, if you want to achieve the advertised fuel economy Honda touts for the PCX, your best bet is to stay under 40 mph. For myself, I can't do that because all the roads I ride to work and school have a minimum safe speed of 40 mph, and some have a 55 mph limit. This affects fuel economy on my PCX drastically.

[Eiron]

My 2015 seems to get the best fuel economy between 30-35 mph.

Thanks for that - is that based on the onboard economy meter (which I think the 2015 model has)?

Yes, based on the instant-readout onboard computer.
The other factor to consider is wind drag. You can gain a few mpg by adding a real windscreen if you don't already have one.
Also, the faster you go the more wind drag you experience. So, faster speeds have that going against them, too.

[j.d.b.]

My 2015 seems to get the best fuel economy between 30-35 mph.

This---^
Generally speaking the best economy will be had at the fastest speed before invoking air resistance. On a calm day, on level ground, 30-35(mph) is about the best.

[TheMaverick]

Thanks everyone.

In the absence of an onboard computer I'm also going to collect a bit of data as to how much fuel is remaining as each segment of the display changes - should be able to use that to work out if I need to back off the throttle at all on some of my longer runs.

[wangsuda]

My 2015 seems to get the best fuel economy between 30-35 mph.

This---^
Generally speaking the best economy will be had at the fastest speed before invoking air resistance. On a calm day, on level ground, 30-35(mph) is about the best.

I've noticed this as well. For me, between 50-60 kph is the most efficient. Also seems to be the best overall speed for my PCX, in terms of control and handling.

[ONTWOWHEELS]

The highest consumption i have noticed for the new PCX 125/2015 modell in the breaking in period and after 750 kms i opened the throttle to 1/2-3/4 with travelling speeds from 70 to 100 in open road is 2,3 l/100kms



That means that it can travel without problem for about 300 kms and there will be a spare of 1,1 litter in the 8 litters tank.

Previous modells with 6 litters tank must travell for about 250 kms without any problem but close to the minimum.
Otherwise i think you must have a valve check.

To say how happy toy must be i will tell you that my SH 300 has a consumption to open road (of course with higher speed up to 130-140) which is from 3,25 up to 4,5 l/100km with a 9,1 litters tank. That means that if i travell to highway with a speed of 130-140 i must refill after 140-150 kms otherwise i might have failure to electric pump which is not cheap to change.


ps :As you see scoots travell just fine for those who say they are only commuters :

[TheMaverick]

Thanks. Mine is a 150, with 5.9l tank. At around 50 km/hr I get about 250km per tank, but wide open only 120 to 150km depending on wind (to start of last segment flashing).

[gn2]

An engine running at 2000 RPMs, and doing 55mph in fifth gear is using as much fuel as the same engine running at 2000 RPMs in sixth at 70 mph.

Only if the fuel input remains constant at 2000rpm regardless of other factors.
But does it...?

[TheMaverick]

An engine running at 2000 RPMs, and doing 55mph in fifth gear is using as much fuel as the same engine running at 2000 RPMs in sixth at 70 mph.

Only if the fuel input remains constant at 2000rpm regardless of other factors.
But does it...?

I'm no rocket scientist, but I would have thought that if the RPM is constant then the amount of air moving through the engine must be constant - and the fuel/air mix would be most efficient at a give ratio (so no need to change it) - so therefore fuel consumption would be more or less constant.

But in practice I don't think that's the case - not sure why.

[you you]

. that last little twist of the throttle seems to increase consumption quite considerably

Isn't that the answer to your question?

[iceman]

The built in gauge is fairly accurate except just after filling up from near empty when it takes a while to settle down - mine seems to be within a few mpg compared to real figures. Why not just use that and ride for the conditions or limits of the road and with a personal preference for speed within that.
Remaining fuel seems good - from near brim I can get about 135mpg and 230 miles trip soon as the bar starts flashing. I pushed it once and did just over 240 miles and still had duel left.

[TheMaverick]

The built in gauge is fairly accurate except just after filling up from near empty when it takes a while to settle down - mine seems to be within a few mpg compared to real figures. Why not just use that and ride for the conditions or limits of the road and with a personal preference for speed within that.
Remaining fuel seems good - from near brim I can get about 135mpg and 230 miles trip soon as the bar starts flashing. I pushed it once and did just over 240 miles and still had duel left.

Mine's a 2014 model - so no trip computer - only the fuel gauge.

[iceman]

The built in gauge is fairly accurate except just after filling up from near empty when it takes a while to settle down - mine seems to be within a few mpg compared to real figures. Why not just use that and ride for the conditions or limits of the road and with a personal preference for speed within that.
Remaining fuel seems good - from near brim I can get about 135mpg and 230 miles trip soon as the bar starts flashing. I pushed it once and did just over 240 miles and still had duel left.

Mine's a 2014 model - so no trip computer - only the fuel gauge.

So is mine, '14 reg LED model. No trip computer but the meter has a trip miles function so I reset it each fill-up (it's one of the button presses - mpg, trip, total) but as for economy, the built-in mpg (or litre) gauge is very good so why bother with anything else.