Fuel octane ratings and Engine damage

[SaferRides]

Not a good idea to run a Euro car on NZ 95, let alone 91, but the knock sensor should have prevented any damage.

No responsible dealer should be selling used import VW's anyway.

I should have put a smiley after the 2nd comment.

To be fair, Marsden Point 95 is better fuel than it used to be, but every vehicle I've had that required 95 has run better on 98.

[F5 Dave]

Errrrrr. Read the manual you say? Shit, I never thought of that. Fuck.

wonder if my rings and pistons are crumbling as we speak?

Stop panicking. My Tiger speced for 95. Actually the previous owner had the pistons replaced as they broke. Not sure if he ran 91 but I suspect so. I put a label on the cap for next owner.

675 is speced for 91.

In NZ was use, , , erm either RON or MON, but they differ slightly. 100 octane is like AV gas so no road vehicle will spec that. Think US use the queer high number system.

[Mike.Gayner]

I've had first hand experience with many of the aforementioned vehicles, and continued use of 91 will kill these engines. Especially the Highline model with the 1.4TSi twin-charge engine (super and turbocharged). I'm not in the slightest surprised her engine was damaged.

That's exactly the model in question, too.

http://www.nzlii.org/cgi-bin/sinodis.../2019/177.html

The vehicle is a 2010 Volkswagen Golf TSI which has a 1.4 litre petrol engine.

[F5 Dave]

Oh no my tyres cut out. I wasn't told they needed air in them.

And my ice cream melted when I left it in the car.

[HenryDorsetCase]

Oh no my tyres cut out. I wasn't told they needed air in them.

And my ice cream melted when I left it in the car.

Honestly, ice cream is one of my favourite foods. No wonder I am so fat.

[TheDemonLord]

Speaking of Melting etc.

I'm not sure if this is due to different Octane ratings, but I remember something about incorrect fuel causing parts of the engine to run much cooler than they should, due to the difference in energy required to vaporise the liquid into a gas for a combustion.

[HenryDorsetCase]

aH-lDh3rVFQ




Here is a clear explanation with examples of pre-ignition and detonation. From the damage described to the VW Golf in the news article it sounds like it was detonation.

My VW Golf mad mate ran/runs all his on 98.

[F5 Dave]

Speaking of Melting etc.

I'm not sure if this is due to different Octane ratings, but I remember something about incorrect fuel causing parts of the engine to run much cooler than they should, due to the difference in energy required to vaporise the liquid into a gas for a combustion.

That's a snippet of no mixed with perhaps methanol stories which are in no way relevant. So just no

Maybe also confused with the light gasses that evaporate quickest . These really help starting a cold engine. Old gas may make it hard to start some engines.

Gas stations have measures to try stave off this loss of light gasses . Usually tall pipes at the side, but you dont always see them.these days.

[F5 Dave]

Most people think pistons are pushed down by carefully timed explosions.
They are not. There is a fire lit which very quickly burns to increase the temperature and thus via Boyles law the pressure.

If there were explosions it would destroy the engine components. And indeed detonation is just that with the end gasses.

[TheDemonLord]

That's a snippet of no mixed with perhaps methanol stories which are in no way relevant. So just no

Maybe also confused with the light gases that evaporate quickest . These really help starting a cold engine. Old gas may make it hard to start some engines.

Hairy Muff, Now that you mention Methanol - that does ring a bell.

[Motu]

aH-lDh3rVFQ




Here is a clear explanation with examples of pre-ignition and detonation. From the damage described to the VW Golf in the news article it sounds like it was detonation..

Detonation will shatter rings...and detonation is post ignition, not pre ignition. The knock sensor will retard ignition timing to control pre ignition, but post ignition is a bit harder to control. I will run my Euro car on Gull 98 for a trip when it is the same price as 91 in town, and get better fuel economy, but around town driving makes no difference. If I damage the engine in my $500 car, I will have to replace it with a $600 car.

[spanner spinner]

This ruling makes a change, usually it's the dealer who gets to pay for the customer's ignorance. I have worked in the automotive industry for many years and have seen many disputes where the customer is proven to be in the wrong as in this case be due to some feeble excuse from the customer the ruling goes against the dealer.