Petrol ?

[Hickky 3,131]

9 hours ago, Jamesco said:

@Hickky you made this post international, so...in Qatar there is only one supplier, easy 😆. We have a choice of 91 or 95 octane, the latter they call 'super'. Probably my Pajero & NC would be fine on either, I do tend to go for 95 RON....I always wonder where the local chaps with their Lambos /Ferraris/ exotica get their fuel from, or do they just stick 95 in there cos it's called 'super'

You are lucky, 95 RON is nowadays a top quality fuel. I think, but not certain, that our standard petrol is 91 RON and the additive laced stuff is 95. In America their cheapest stuff is 87 RON, medium is 91 and top fuel is 93RON. It is also true that quoted MPG and engine power is (in the USA) based on 93 RON. 

With modern fuel injection, particularly for cars that have injectors that fire into the cylinder itself, instead of just before the inlet valves, the computers will adjust the amount of fuel  injected according to its octane, the worse the octane, the more fuel is forced in. So slightly worse fuel consumption in the USA than over this side of the pond. However the number and quality of computers in a modern car (and to a certain degree, a modern bike) are much more than a Boeing 737, that still use 16 bit processors. (Even less than our NHS, at least they use 32 bit) One of the reasons the Max has had such a troubled time. But cars have so many sensors, it's no wonder they all show the 'check engine light' from time to time, when the cheap rubbish sensors go wrong.

Motorcycles don't have the same pollution equipment that cars do. Euro 5 imposes the type of catalitic  converter fitted, but, as there are no pollution checks at an MOT, nor need for much else, as long as the engine is built with the converters and accurate fuel injection, it passes. As (I hazard a guess here) about 30% of bikes have dumped the cat (decat) and fitted noisier cans, as long as the fueling computers are within parameters, the bike will run fine, although if you make the machine with less restrictions on the exhaust, it may be prudent to run high test petrol, unless you have a special electronic box that will compensate.

It has always staggered me that Japanese engines in the 1970s that had a red line of 10,000 still ran on 2 star petrol, 92 octane. Racing engines were always run on 5 star petrol which was leaded and was 101 RON at that time but the Japs recommended 2 star! Blimey, I used to run my ex GPO 850 mini van on 4 star, it 'pinked' if I used 2 star.

I have also been told that Octane is not a measure of pent up energy stored within the petrol and 5 star contains less bang than 2 star. If anybody here knows how this works, please let us all know.

[davebike 943]

My experence as both a rider often of small bikes and a mechanic is to recomend teh Shell BP or ESSO  and to avoid the smaller makes

Petrol is the same but adatives may not be 

We see lots of problems with bikes that do not get used a lot  always with supermarket or other "cheap" fuel the cure is often a tank of "good" fuel and a can injector cleaner + a dealers decoke!!

I was told the issue is lack of stabliser in "cheap" fuel and that Tesco only rated their basic fuel as good for  3!  weeks

I also avoid if possiable small / supermarket stations  having stoped every 5 miles comming back from Wales followling a fill in a Tesco to drain water out of my C90's carb and 60 miles on a tank not the usual 90+  guess paying over £1 a liter for water pissed me off! old fuel systems make finding water easy but a pain !

[KingJames 1,262]

I'm of the view there is something different between the brands too and assumed it was a post refinery step.  The brands vary their different RONs and ethanol amount all at pumps in the local area so there must be something different going on.  Fully get the limited refinery point, but something is going on.  Fortunately ESSO is the cheapest around here matching Tesco.  I've never found the super petrols make a difference on my non super cars, inc the silly 'sports' car with turbos.

[Bugsy 175]

Hmmm, I use my local independant petrol/minimart/MOT/ station that is just up the road. They know me by sight, don't get antsy if I walk about with a helmet on my head, are happy to ignore me while I pick up a sandwich and Mars bar for a day out and don't bother me with a printed receipt. Oh, and the petrol is, er, petroly and saves me from pushing the bike. What's to avoid or not to like? It's all the same juice, just the sellers that vary.

[Jamesc 3,665]

@Hickky I think in US/Canada they use AKI rather than RON rating, hence their fuel appears to be lower octane to us but probably isn't

Edited October 12, 2020 by Jamesco

[bahnstormer 905]

41 minutes ago, Jamesco said:

@Hickky I think in US/Canada they use AKI rather than RON rating, hence their fuel appears to be lower octane to us but probably isn't

 

They typically use PON, which stands for Pump Octane Number.  The PON is the average of the difference between RON (Research Octane Number) and MON (Motor Octane Number).  So, petrol that's rated 98 everywhere else would be something like 93 in the US.

 

The higher the octane rating, the more compression the fuel can take take before it begins to detonate or "pink" when ignited.  V-Power is 99, hence why I use it in the cars, which are JDM imports and mapped for their higher octane fuel. 

Edited October 12, 2020 by bahnstormer

[Jamesc 3,665]

@bahnstormer ref the pinking I had an Rx7, that liked Tesco 99 (not the ice creams)

[makman 975]

I fill the mighty K1200R with Sainsburys 99RON as the station is 4 miles from me and is cheaper than the local 95RON Texaco/Harvester options. The bike likes it as well. Car gets cheapest stuff I can find, usually Sainsburys or Asda. 10p/litre cheaper than local prices.  Some places are really taking the piss at moment with prices.

[Empty_Ten 454]

I have always ran the cheapest stuff possible from supermarkets or the small chains of cheap fuel.  
 

I think a combination of them frequently getting fresh deliveries, and me frequently refuelling means I’ve never had an issue.  
 

Saying that, I left a full tank in my blade last year and it wasn’t started for about 4 months.  When I did start it, it spluttered a bit but was ultimately fine.

[bahnstormer 905]

5 hours ago, Empty_Ten said:

I have always ran the cheapest stuff possible from supermarkets or the small chains of cheap fuel.  
 

I think a combination of them frequently getting fresh deliveries, and me frequently refuelling means I’ve never had an issue.  
 

Saying that, I left a full tank in my blade last year and it wasn’t started for about 4 months.  When I did start it, it spluttered a bit but was ultimately fine.

 

My little Toyota Glanza-V had £10 of V-power, in September.  Last year.

 

It still fires up and runs perfectly .

 

Poor thing hasn't been used properly for about 18 months as I'm in the middle of restoring it.  Just got to sort the handbrake and she'll (hopefully!) be back on the road, then going for a respray as the paint is awful.

 

Edited October 13, 2020 by bahnstormer

[bahnstormer 905]

Oops, double post.

Edited October 13, 2020 by bahnstormer