What Petrol?

[Rodger Wabbit]

I have managed to use my first full tank of petrol now and i am wondering is it worth filling up with the optimax or the BP special thing, or should i save my money and just put in normal unleaded?

[jonboy]

Save your money. ;)


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[rukus]

I heard diesel was a good alternative :D

please, please, don't take that seriously!!! :lol:

[Rodger Wabbit]

"Puts diesel in" :shock: You recon i get more MPG :lol:

[rukus]

"Puts diesel in" :shock: You recon i get more MPG :lol:

yup... 100 miles on the back of a tow truck!!! No fuel used! now that's good mpg!
:lol:

[simon-temple]

everytime I fill up I have this fear that I've made the mistake. As I'm staring around the forecourt I get that moment of fear! Arrhg!

Look down, ah...green handle.

Has anyone tried the funky petrol? did you notice any difference?

[northwind]

I use Optimax whenever possible, I enjoy the placebo effect. I don't honestly know if it does me any real benefit over most regular unleadeds, but I usually steer clear of Jet garages, I'm sure they sell a lower quality or octane or something, both my bike ran less well with it in the tank.

[Viney]

I use optimax/BP Ultimate/Super unleaded.

Notice a slight difference, but not a huge one. Just use it, becuase i can

[Warren]

I use Optimax whenever possible, I enjoy the placebo effect. I don't honestly know if it does me any real benefit over most regular unleadeds, but I usually steer clear of Jet garages, I'm sure they sell a lower quality or octane or something, both my bike ran less well with it in the tank.

my advice exactly.

the optimax in my 125cc seemed to make it quicker.
but in the CBR6 it doesnt make a difference. just notice a bit of weight reduction - especially around the pocket area's

[a1a]

I always use named brands of petrol and use the lowest octane that my engine does not ping or detonate on.
SV650 = 87 octane
VS1400 = 92 octane
Those are USA specifications! Cheers

[MattTheLoony]

Now I see why the petrol is so cheap over there, thats much lower octane than our stuff. Think even the cheap stuff is 94/95 here isnt it?

I havent tried any of the super's but was wondering about it, might give it a shot and see, i always use the BP ultimate in the car

[SV650S Chick]

Now I see why the petrol is so cheap over there, thats much lower octane than our stuff. Think even the cheap stuff is 94/95 here isnt it?

I havent tried any of the super's but was wondering about it, might give it a shot and see, i always use the BP ultimate in the car

petrol cheap in the usa? wow i would hate to know your prices over there.
as for me i use 92 octane in my bike all the time.

[northwind]

See, this is pretty funny... Even the US thinks their petrol is expensive :) SV650S Chick, you have some of the cheapest pump prices in the world...

[Stig]

yeah and we have one of the most expensive :x :x :x :x

[SV650S Chick]

sorry to hear that. but i could imagine paying more then $2 for a gallon right now it's $1.79 and i hate the price.

[jonboy]

So imagine paying $6-7 a gallon, like we do. :twisted:


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[SV650S Chick]

:shock: OMG, I'd flip.

[Warren]

this thread reminds me
i think it was this forum but someone was asking about converting an SV650 to run on deseal.
know i know a bit more about engines and how they work , i ask myself




WHY ?

[northwind]

Price of fuel doesn't bother me in the slightest, to be honest... I'll burn a tank or two in an average week, it's just one of the costs of looking very cool while going very fast : 8)

Bikeageboy, my brother's obsessed with the idea of a small diesel engine for a bike... He reckons it could be done quite easily for a lower-performace engine, and that a diesel powered scooter or light road bike would be far more efficient than a petrol burner- less parts in a diesl engine apparently. Personally, I can't see how you'd ever convince bikers to ride a diesel... Unless it was that crazy turbine bike :shock:

[Clunk]

I remember reading a couple of years ago about a diesel engine fitted to a kwacker 650 trials bike. The army were going to use it, not heard anything about it since.

I remember being on hols in Florida a few years ago and Petrol was under $1 a gallon and they were moaning about price rises :shock:

It seems bizare that the biggest polluter in the world gets the cheapest fuel.
We pay massive taxes to combat pollution ( never understood the link between paying more money and causing less pollution :? ) whilst the yanks couldn't give a **** and burn fuel like there's no tomorrow.

Give it 50 years and there wont be any left :cry:

[Liam]

I have managed to use my first full tank of petrol now and i am wondering is it worth filling up with the optimax or the BP special thing, or should i save my money and just put in normal unleaded?

I switched to using Optimax in my SV a few months back and I reckon I get an extra 5-6 miles a tank, which would make sense as optimax and ultimate have a higher energy density (by some 3% or so). Shell & BP also claim extra additives to keep your engine in good nick, but how do you prove that unless you run 2 identical machines for 50k miles.

Liam

[chazzyb]

I always use named brands of petrol and use the lowest octane that my engine does not ping or detonate on.
SV650 = 87 octane
VS1400 = 92 octane
Those are USA specifications! Cheers

Remember folks, these are MON (motor octane number) ratings rather than RON (research octane number), which we use in Blighty.

[jonboy]

So how do they directly compare?


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[embee]

I always use named brands of petrol and use the lowest octane that my engine does not ping or detonate on.
SV650 = 87 octane
VS1400 = 92 octane
Those are USA specifications! Cheers

Remember folks, these are MON (motor octane number) ratings rather than RON (research octane number), which we use in Blighty.

You'll usually find they are quoted as "Pump Octane Number" in the USA which is the average of the Research and Motor

Pump = (R+M)/2

For most commercial fuels there's usually around 7 to 9 numbers difference between them (MON = RON-8 typical), so Pump = RON-4 give or take a bit. It varies from fuel to fuel a little.

The different numbers both are a comparison to a mixture of iso-Octane and n-Heptane (so 95 "Octane" behaves like a mixture of 95% iso-Octane and 5% n-Heptane), but the test conditions (speed/temp/load etc)are different so the 2 tests come up with different numbers.

Why, you might ask?

Well, it depends whether you're running constant light load or transients into heavy load etc as to how the particular fuel behaves, and there isn't one single test which will characterise the fuel, so there are several different tests.

The USA habit of describing fuel as (R+M)/2 is actually more useful in real life than simply RON.

--------------------

You can't keep trouble from coming, but don't give it a chair to sit on.

[BillyC]

I always use named brands of petrol and use the lowest octane that my engine does not ping or detonate on.
SV650 = 87 octane
VS1400 = 92 octane
Those are USA specifications! Cheers

Hang on a1a, I think you've possibly misunderstood the nature of petroleum.

The lower the octane number, the more likely you are to get premature detonation.

Low octane fuels, such as cheap motor-gas require less energy to detonate, and may do so in a hot high-compression engine, such as a motorbike. To avoid this pre-ignition, you should up the octane rating of your fuel.

Higher octane fuel requires more energy to ignite, and can withstand higher pressures and temperatures before detonation - this ensures that detonation occurs only when the spark plug fires.

If you want to look after your SV, with it's compression ratio of 11.5:1 - then you should be trying to get a fuel with Octane levels in the 90's, rather than the low compression US fuels that most American cars are designed to run on.

Just a friendly word of advice.

[chazzyb]

So how do they directly compare?
.

No idea at all! I just happened to know they use a different system, which is why their numbers are different/lower. :D

Or look here (http://en.wikipedia.org/wiki/Petrol).

Ha, embee's been along already - I shall now read and learn.

[BillyC]

MON and RON are basically the same test, but basically completed to different specifications.

MON tests higher in the rev range than RON, on which to base the average Octane level.

Generally speaking, they produce the same kind of figures, except when you get into the higher Octane levels where high compression engines will sap more power from the fuel - giving a higher octane ranking.

Comprende?

[embee]

I'll just throw in a little extra nosegay here, since we're on the subject, and the terms get bandied about. :?

Normal combustion - the flame starts at the spark plug, the "kernel" or small ball of fire slowly grows to a threshold size when the flame front will then progress at a more or less characteristic speed across the combustion chamber in a nice progressive controlled manner. Flame speeds are actually in the range of a few tens of metres per second.
It is not useful to describe it as an explosion. A normal burn will take up maybe 30-45degrees of crank rotation (depends on load, temperature, mixture preparation, A/F ratio, exhaust gas dilution, crank speed to some extent)

Detonation - aka knock, pinking (although very strictly speaking there are differences between knock and detonation, but that's another story).
This is a phenomenon where once the burn has started at the plug normally, the pressure and temperature increase as the burn gets going will cause mixture ahead of the flame front to chemically change into substances which will spontaneously react without needing the flame. You then get pockets of mixture going off very rapidly before the flame arrives (much more akin to an explosion, reaction rates can be an order of magnitude faster than a normal burn).
Noise is characteristically in the 6kHz (or harmonics, 12kHz etc) range, so has a similar sound in most engines.
Mild detonation causes little harm though isn't recommended, severe cases cause component temperatures to increase and ultimately can cause fatigue cracking of piston ring lands (usually the second land which supports the top ring).
It is the properties of a particular fuel which determine how easily it undergoes these transformations that give it its Octane rating.

Pre-ignition - totally different to detonation. As the name suggests, the mixture starts burning before the spark occurs, usually caused by an excessively hot component (most commonly a spark plug of the wrong grade, loose plug, badly seating exhaust valve etc) or glowing carbon deposits. Because the burn starts early, the pressure and temperatures rise dramatically as heat is released during the compression stroke. This puts massive loads and temperature into pistons, which can literally melt, or expand so much they get too big for the bore and seize.
Failure is usually in seconds, and if you're lucky puts a little hole in the piston crown, if not the whole piston and bore start to weld together and look a total mess.
Of course this massive heat input and temp/pressure rise will also result in disastrous levels of detonation and sounds pretty awful usually.

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troubles are like babies, the more you nurse them the bigger they grow

[wyrdness]

So imagine paying $6-7 a gallon, like we do. :twisted:

It's not quite that expensive. Remember that US gallons are smaller than imperial gallons.

81p/litre works out about $5.50/US Gallon. Considering that it's going to run out in a few years, I think that it's far too cheap in the US.

[BillyC]

Yeah it's more like $5/US Gallon mark...

However, aviation jet fuel is the one that should be more expensive. By international agreement it has no tax imposed on it, and retails at about half that, but is used in massive quantities.

[hobsonr]

whatever you do, don't use supermarket fuel (Morrisons), it's crap.
My SV650S shudders like hell between 60-80 mph, it's fine after that but I reckon I lose 5-9 mph at the top end.

Stick to well known brands like BP or Shell.

Black SV650S (2000)

[wigan650s]

DIESEL BIKE (http://www.motorbikestoday.com/features/Articles/diesel_bikes.htm)

400 miles to a full tank...nice :shock:

[northwind]

Excellent :) Therehas to be a market for that, surely? Not for me, but farm use, that sort of thing... Not to mention bikers on a budget.

[chazzyb]

Excellent :) Therehas to be a market for that, surely? Not for me, but farm use, that sort of thing... Not to mention bikers on a budget.

Hmm, military use only I'd guess. The army want diesel-engined vehicles so they only have to cart one fuel around.

[northwind]

Aye, but when all you need is a low-performance efficient mover- ie you're chasing a sheep on a hillfarm, or similiar, or you're wanting a cheap-to-run commuter, it'd make sense... Especially for farm use, where you've got access to red diesel, or is it pink, for of-road-use only...

[SV650Samji]

how many miles do you guys get on a full tank of fuel and how far can you go when the fuel lights comes on?

I've done 135miles and the fuel light has come on...

[MattTheLoony]

I've not been through many tanks but got about 125 out of them

[BillyC]

how many miles do you guys get on a full tank of fuel and how far can you go when the fuel lights comes on?

I've done 135miles and the fuel light has come on...

That's about average... The best I've managed is 155 miles, but it was too dull for words! :lol:

[Clunk]

how many miles do you guys get on a full tank of fuel and how far can you go when the fuel lights comes on?

I've done 135miles and the fuel light has come on...

This question seems to come up a lot, if you search for fuel comsumption you'll get loads of answers.

I get about 130-140 before the light flashes, then you're probably safe for at least another 20-30 miles. Most I've ever done is 175 miles on a tank, and it was a bit scary towards the end.

[Graham]

Mine goes about 150 miles before the flashing light. I then do another 40 miles before refilling. I do this EVERY week commuting to work. She's pretty well running on vapors by then . My best estimate is that it holds only 15.8 litres not 16 like it's supposed to

[a1a]

I always use named brands of petrol and use the lowest octane that my engine does not ping or detonate on.
SV650 = 87 octane
VS1400 = 92 octane
Those are USA specifications! Cheers

Hang on a1a, I think you've possibly misunderstood the nature of petroleum.

The lower the octane number, the more likely you are to get premature detonation.

Low octane fuels, such as cheap motor-gas require less energy to detonate, and may do so in a hot high-compression engine, such as a motorbike. To avoid this pre-ignition, you should up the octane rating of your fuel.

Higher octane fuel requires more energy to ignite, and can withstand higher pressures and temperatures before detonation - this ensures that detonation occurs only when the spark plug fires.

If you want to look after your SV, with it's compression ratio of 11.5:1 - then you should be trying to get a fuel with Octane levels in the 90's, rather than the low compression US fuels that most American cars are designed to run on.

Just a friendly word of advice.

Hi BillyC,
I appreciate your response about petrol octane. One should always use the lowest octane that does not cause your engine to ping/knock under hard acceleration. Otherwise you are just wasting your hard earned money. Lower octane fuel burns faster and more completely than higher octane fuel. For this reason if your engine pings/knocks using lower octane you need to use a slower burning higher octane fuel. I'm not going to get into the Mon & Ron methods of grading the fuel. But the principle is still the same, the lower the octane the faster the burn. The higher the octane the slower the burn.
My Intruder VS1400 has 9.3:1 compression, has Vance & Hines pipes and DynoJet kit and pings like hell on the lower/faster burning octane. That is why I use the higher/slower burning fuel for that engine. Both owners manuals state to use a minimum of 87 octane using the RON octane rating.
For my SV650 which is 11.5:1 compression and in stock condition. I use the lower/faster burning octane fuel. Because I do not have any engine ping/knocking associated with hard acceleration or higher engine speeds.
Ride safe & often, Richard