Is cheaper fuel a false economy?

[Bob]

My latest Huffington Post column, in which I test fuel consumption using 95 and 98 Octane fuel, to see if it makes a difference in performance (and so cost):

http://www.huffingtonpost.co.uk/mobi...b_1677319.html

Hope you find it interesting,

Regards,

Bob

[Mort]

Thanks for that - There's no benefit in using 95/98 octane unless your bike/car is tuned to use the extra octane (ie has a high enough compression ratio and the ignition is timed correctly). It if does not then there is no power/economy advantage. 91 should not be used in an engine designed for 95 because you'll get pinking. One possible caveat - using 95/98 is possibly advisable in a lower tune engine if you are hammering it around a track to stop possible pinking at higher rpm.

[george formby]

I dunno why he was so surprised. Modern engines sip fuel with their pinkie sticking out. The difference in cost at the pump is a bigger percentage than the difference in efficiency if your actually driving or riding with frugality in mind.

The AA was on the box last night claiming that the cheap Gull petrol with 10% ethanol is false economy. I cried foul on this, no specifics of the testing done, conditions, vehicles etc. I would rather save at the pump & use my head & common knowledge to make the most of what goes in the tank.

[avgas]

Fire your editor. Is it a bike review or a fuel review?

Is Cheap Fuel a False Economy? Honda NC700S Review

• The bike: a 2008 Suzuki GSX650F with 19,000 miles on the clock.
So there is a need to look at ways of improving economy. And Honda really took the bull by the horns, creating the NC700X - a parallel twin featuring effectively half a Honda Jazz car engine... and a reputed 78 miles per gallon range.

[Jantar]

I have found even more extrordinary results here in New Zealand. Over my last 3 bikes I have kept a very accurate record of fuel usage with some suprising results.

My 1996 VStrom would not run well on 91 octane. It would tolerate it on a trip, but not when commuting, so the aim here was to see if there was a difference between fuel brands. I found only minor differences with Shell being best, Caltex, Challenge and BP equal, and Mobil slightly behind. BP 98 was slightly better than than all others, but not by enough to warrant the extra cost. This test was carried out over two years and aproximately 40,000 km.

My second VStrom gave very suprising results. First of all it felt as if it ran better on 91 than 95 or higher, and it wasn't long before the results confirmed it. The Mobil test is not significant as Mobil is the only fuel I don't have a fuel card for, so I use this brand only when there is no alternative. This test is over 2.5 years and 45,000 km.

BP 91 - 16.6 km/l __________ BP 98 - 16.0 km/l

Caltex 91 - 16.5 km/l _______ Caltex 95 - 16.5 km/l

Challenge 91 - 15.8 km/l ____ Challenge 95 - 15.3 km/l

Mobil 91 - 15.1 km/l _______ Mobil 95 - 16.8 km/l

Shell 91 - 17.2 km/l ________ Shell 95 - 15.9 Km/l

Overall 91 - 16.5 km/l ______ Overall 95 (or higher) 16.2 km/l


Now I'm trying the same thing on my GSX 1250 FA. With only 9 tanks of fuel its still too early for any conclusive results, but so far 91 octane is showing a clear difference over 95. This test is over 2 weeks and 3,000 km.

BP 91 - 17.7 km/l __________ BP 98 - 16.8 km/l

Caltex 91 - untried _________ Caltex 95 - 17.1 km/l

Challenge 91 - untried ______ Challenge 95 - untried

Mobil 91 - untried _________ Mobil 95 - 16.8 km/l

Z 91 - 18.5 km/l ___________ Z 95 - 17.7 Km/l

Overall 91 - 18.5 km/l ______ Overall 95 (or higher) 17.1 km/l

My results over the past few years show Shell, now Z as being a clear winner, with 91 octane giving much better results than the others.

[Scuba_Steve]

Thanks for that - There's no benefit in using 95/98 octane unless your bike/car is tuned to use the extra octane (ie has a high enough compression ratio and the ignition is timed correctly). It if does not then there is no power/economy advantage. 91 should not be used in an engine designed for 95 because you'll get pinking. One possible caveat - using 95/98 is possibly advisable in a lower tune engine if you are hammering it around a track to stop possible pinking at higher rpm.

yea ^
Thinking it would be interesting to see the results of a higher octane engine (95 std) running the different grades tho. I've seen these 91 engine tests before, same result you're just pissing away money by running higher octane.
But I haven't seen any where they try to downgrade the octane of a 95 engine be interesting to see just what effects it has, if any

[Str8 Jacket]

I've been thinking about what difference the different type of fuels make etc..... I have always filled my bike up with the 98 at Mobil and got at least 350k's out of a tank. The last time I filled my bike at Shell with their 95/96 I only just managed 300k's. Have filled up with Mobil 98 again this time and will see....
I know it's slightly off topic but I can't use 91 or other cheaper alternatives as the bike runs like POOH.

[Akzle]

My latest Huffington Post column, in which I test fuel consumption using 95 and 98 Octane fuel, to see if it makes a difference in performance (and so cost):

http://www.huffingtonpost.co.uk/mobi...b_1677319.html

Hope you find it interesting,

Regards,

Bob

depends on teh vehicle and teh driver and teh definition of "economy"

it represents better economic value from a non-planet-destroying perspective.

my bike will go as far and fast on gull hi octane as caltex or shell hi octane.

i haven't fed anything 91 for a while, but the lawnmower (4 stokka) and chainsaw (2 smokka) don't seem to mind. running premium in the chainsaw tends to warm it up a bit quicker and keep a slightly higher operating temp, gives no better performance or longer cutting out of a tank.

basically, if you can use gull, ethanol or biodiesel, i would encourage you to do so.

sure as shit don't believe the media hype. fill a tank with it and press the kemommeter-odo-trip button and find out for yourself. if you're puttering around town there will be feckall in it, if you like hanging the back end out on the gravel, you might find it a bit sluggish.

i have found a big difference between 91 and 95-96, no difference at all between 96 and 98 (in every vehicle i've had, half dozen bikes, dozen or more cars, nothing newer than 1996)

[Bald Eagle]

I do a standard commute of 54km each way, I've found I get mre km's per fill from BP 98 than I do from Z's high octane

Sent from my MB525 using Tapatalk 2

[Asher]

http://www.stuff.co.nz/business/indu...biofuel-claims
Seems that high ethanol fuels give lower economy...
There was a thread on the rgv forums talking about how the higher ethanol fuels damage the rubber in the hoses and carbs

[Jantar]

I do a standard commute of 54km each way, I've found I get mre km's per fill from BP 98 than I do from Z's high octane

Sent from my MB525 using Tapatalk 2

So what is the difference in km/l?

Have you tried them on a long trip? And have you compared with lower octane fuel and measured the difference?

The point is that even a less efficient fuel may be more economical under certain types of riding.

[bogan]

I wouldn't rely on any results that don't check the emissions as you are running. Economy is too dependent on the state of tune. A lot of modern vehicles use O2 sensors to self tune a little, so if you got one of those its easier to figure what is best for you.

If you got a carbed or basic FI engine, it'd be worth figuring out what the theoretical/practical most economical fuel is, then economy tune it to suit. Just pouring it in the tank isn't going to get you the best savings.

On the savings topic, much more can be saved by changing your driving habits, drive economically, and drive less often.

[Paul in NZ]

I've found that whatever fuel I use I end up enjoying myself so much I can't remember why I cared about the mileage in the first place. Mind you the trophy gets around 70 to 75mpg at cruising speed anyway so who cares.

[Jantar]

....
On the savings topic, much more can be saved by changing your driving habits, drive economically, and drive less often.

You may be right, but that isn't why I take note of fuel consumption. I just want the most riding pleasure for the least dollars.

Changing my riding habits would probably lessen my riding pleasure. Riding economically? That would increase the number of speeding fines. Ride less often? Then why bother enjoying motorcycling at all.

[SMOKEU]

What most people don't know is that petrol JDM vehicles are designed to run on a much higher octane fuel than our 91, so even low performance bikes and cars are often more expensive to run on 91 than on 95. People don't generally look at the big picture, and want immediate savings (from cheaper fuel).