petrol octane rating

[Vaim]

I'm trying to do some research on the matter and decide which fuel i should start using.

 

The normal ones here are 95 and 98 and some with additives.

 

So far i've concluded that if your engine is tuned for it, 98 octane fuel should result in more hp and better mileage.

I have not yet found out if the mk3 superb gets any better results in the real world.

 

What do the owners here say?

Are you using standard or premium fuel and have you felt/seen the difference?

 

[Jaytip]

My understanding is that higher octane fuel will always be more beneficial for an engine (I could be wrong though) and with petrol prices being what they are these days it would be rude not to fill up with the good stuff.

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[Rainmaker]

I'm awaiting a 2.0 TSI so I'd also be interested in whether the S3 requires 98 or 95. Usually the older models have all asked or 98 inside the fuel filler cap, but I've read mumblings (with nothing concrete) that the newer ones are mapped for 95 RON.

 

Basically if the filler flap says 98 (95) it means mapped for 98 but can retard timing to cope with 95. In that case it'll benefit - both in terms of power and MPG - to use Shell VPower 99 or Tesco Momentum 99. If it says 95 RON then it's basically a waste of money to use anything but a quality 95 RON. Intermediate fuels (i.e. 97 super unleaded) are useless as a car mapped to 98 won't switch the timing until it detects 98 or above, which leaves VPower and M99.

Edited 31 January, 2016 by Derv

[Rainmaker]

My understanding is that higher octane fuel will always be more beneficial for an engine (I could be wrong though) and with petrol prices being what they are these days it would be rude not to fill up with the good stuff.

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There is an argument for the additive detergent packages, certainly. Shell and BP both have videos on YouTube showing regular 95 (their own) versus VPower/Ultimate which is massively cleaner after x thousand miles. The intake valves especially are much dirtier on the lesser fuels. As you say at current prices it wouldn't do any harm, but as per the OP's question I think yes there's a difference (as stated in the manual) and yes it's definitely worth running 99 RON provided the filler flap asks for 98+.

[BillyJim]

I tried looking into the RON ratings and when I saw this page I came to the conclusion that so much of it is just marketing hype. How can the same fuel have a rating varying between 97 and 100 RON depending in which country you happen to be at the time?

Shell state in the Netherlands it is 97 RON and, hey, that is the home of Royal Dutch Shell!

[Rainmaker]

I tried looking into the RON ratings and when I saw this page I came to the conclusion that so much of it is just marketing hype. How can the same fuel have a rating varying between 97 and 100 RON depending in which country you happen to be at the time?

Shell state in the Netherlands it is 97 RON and, hey, that is the home of Royal Dutch Shell!

 

The RON definitely isn't marketing hype, in fact it's strictly legally controlled lol. You can raise and lower octane significantly simply with little tweaks (an additive, ethanol proportion etc) without even touching the base fuel. If it says 99 RON you can bet your bottom dollar it is. In fact due to the way fuel is distributed it may be even higher, as the fuel starts marginally higher than the labelling to account for the (slow) degradation in octane which naturally occurs over time in transit and storage.

 

There are variations in the way companies work, but it's the same end result. For example BP Ultimate is (was?) totally ethanol free, and the base fuel is specifically refined to 97 RON in and of itself. That's part of the reason it's so much more expensive (proportionally) to other fuels. Shell VPower is a more closely guarded commercial secret, but does contain some ethanol as well as other additives. Tesco M99 is actually made from cracked naphtha (a fraction different from petroleum). When you crack naphtha you end up with very high octane petroleum, to which Tesco (via the Greenergy petrol refinery they own) add significant levels of ethanol/methanol and oxygenates.

 

Various countries have differing traditional octanes (100, 98, 95, 91 etc) and oil companies obviously tailor their base fuels and blends to suit this. Likewise OEMs usually alter the ECU maps, timing etc to fit in. For example the Mazda 6 SkyActiv engine has 14:1 compression as sold in the UK market, based on our usage of 95 RON fuel. In the USA the same car is sold with the engine set up with 'only' 13:1 compression, to suit their standard 91 RON equivalent fuel.

 

Just because Shell sells fuel on both sides of the Atlantic, don't think it's all the same RON bar the 'marketing hype'. In fact you'd be paying a lot more at the pump in the US if you wanted 95 or 99 RON, rather than 91. Thus in Europe; same brand, different octanes (but the same detergent packages etc). Don't confuse branding (VPower) with the underlying product. For example even Coca Cola is totally different in the UK and USA, using sucrose in the UK and only corn syrup in the USA. Same name and packaging, totally different ingredients and taste. 

Edited 31 January, 2016 by Derv

[Prykey]

I tried looking into the RON ratings and when I saw this page I came to the conclusion that so much of it is just marketing hype. How can the same fuel have a rating varying between 97 and 100 RON depending in which country you happen to be at the time?

Shell state in the Netherlands it is 97 RON and, hey, that is the home of Royal Dutch Shell!

So what does your handbook state that you should use in your 280PS engine BillyJim?

[philsmith]

I did the first three fill ups using 98 as stated on the filler cap.(well 97 as I never saw 98 in the stations I filled up in) 

Last time I had to put in 95 as I was empty and this was all the station had. 

Can't say I have noticed any difference in performance or consumption.

 

Will refill with the higher octane next time though.

[Nick_H]

I'm using almost exclusively BP 97 Ron in mine.... Mostly because it's convenient as I pass a station on the way to work.

[Ootohere]

Which Country are you in.

 

The UK has 95 Ron Unleaded.

The Super Unleaded UK is 97 ron (minimum)  Sainsburys, Esso, BP, Gulf.  So not 98 ron. (But it could be sometimes).

 

Tesco Momentum 99 & Shell V-Power Nitro+ is 99 Octane (Minimum) in the UK. Shell V-Power Nitro+ can be higher Octane on Mainland Europe.

 

http://volkswagen.co.uk/need-help/owners/Fuel

Edited 31 January, 2016 by GoneOffskiroottoot

[BillyJim]

I'm using almost exclusively BP 97 Ron in mine.... Mostly because it's convenient as I pass a station on the way to work.

Same here, but not BP. 97 RON Super Unleaded from the supermarket. I've used 95 RON on one occasion and even 100 RON in Germany (Shell V-Power Racing). TBH I've noticed no difference in performance or consumption, only the price, though if I were to use a different fuel long term it may tell a different story.

[BillyJim]

So what does your handbook state that you should use in your 280PS engine BillyJim?

Unleaded petrol 98/(95) RON / ROZ

We recommend using unleaded fuel with an octane rating of 98 RON or higher. Unleaded petrol 95 RON can also be used but this results in a slight loss in performance and slightly increased fuel consumption.

 

In an emergency petrol with the octane ratings 91, 92 and/or 93 RON can also be used, but may result in a slight loss in performance and slightly increased fuel consumption. Continue driving at medium engine speeds and minimum engine load.

[ant2ant]

Does anyone here use Millers Oils fuel additive. This cleans and adds 3 octane.

[BillyJim]

Does anyone here use Millers Oils fuel additive. This cleans and adds 3 octane.

And may be used as an excuse to invalidate your warranty.

From the user manual...

 

Fuel additives

Unleaded petrol in accordance with the EN 228 standard meets all the conditions for a smooth-running engine. We therefore recommend that no fuel additives are used. This can result in considerable damage to parts of the engine or the exhaust system.

[Ootohere]

'Tesco Momentum 99' adds 4 octane over the 'Tesco Unleaded' 95 ron for 5 pence a litre more, nationwide almost.

So £2.25 extra for 45 litres when filling up. 

You are not going to find any octane booster that actually works for less cash money.

[ant2ant]

'Tesco Momentum 99' adds 4 octane over the 'Tesco Unleaded' 95 ron for 5 pence a litre more, nationwide almost.

So £2.25 extra for 45 litres when filling up. 

You are not going to find any octane booster that actually works for less cash money.

Millers petrol ecomax works out as 2.5 pence per litre.

[Ootohere]

& adds 2 Octane does it not?

[Rebelred]

So you shouldn't add fuel additives to either petrol or diesel engines in modern cars?? I always put half a bottle of 'Diputane' in both our cars every 6 months. I thought they are good for the car..

[ant2ant]

Just out of interest my fuel filler cap does not show any fuel info just the tyre pressure values and they are in bars. Is it only shown on deisels.

[BillyJim]

Just out of interest my fuel filler cap does not show any fuel info just the tyre pressure values and they are in bars. Is it only shown on deisels.

It's shown on all TSi, where it's probably more relevant than the single option of Diesel models. You may need to slide the ice scraper up to see it.

[fj604]

On my 2.0 TSI 220PS DSG it is 95 RON shown under the fuel filler cap.

[Rainmaker]

On my 2.0 TSI 220PS DSG it is 95 RON shown under the fuel filler cap.

 

Thanks for clearing that up. Seems they've managed to map the newer ones on the lower octane fuel. At today's "lower" prices that's always a good thing as we can take advantage of the sub-£1 a litre stuff! 

[Devonshiredave]

Does anyone here use Millers Oils fuel additive. This cleans and adds 3 octane.

I use Diesel Ecomax. Have done for several years. It definitely helps improve not only economy but quietens the engine and it certainly seems smoother and more responsive.

Put a dose in my son's Passat 130 PD Tdi and he noticed an improvement in economy etc. His words were "it sounds like a tractor" when he refuelled without the Ecomax.

Can't say that I've used the super diesels but might try it and give it a squirt of Ecomax too.

[mikehp1]

I am realy confused after reading this, I am due to pick up my new Superb 220 SEL ex estate on the 1st of March 17 reg I have told the garage to fill it with 98 octane. The answers on this forum have put a question mark on if done the right thing in requesting this, once l have some miles under its belt l will let you know what its doing.

[Rainmaker]

29 minutes ago, mikehp1 said:

I am realy confused after reading this, I am due to pick up my new Superb 220 SEL ex estate on the 1st of March 17 reg I have told the garage to fill it with 98 octane. The answers on this forum have put a question mark on if done the right thing in requesting this, once l have some miles under its belt l will let you know what its doing.

 

98 plus is best for the car, and is what the manual recommends. Don't worry about it and enjoy your new car!