@SurreyJohn   You getting 100% petrol at fuel pumps, but you are getting 100% of what is required in the way of Bio content up to 5%, so that is a litre of petrol is a litre of petroleum, if it has ethanol as well as detergents and anti foam products so be it.

(Ethenol is hygroscopic and winter fuel might well have less in the formuation.)

 

Surprisingly in 2019 Modern UK Filling stations and their tanks do rather well with the fuels and 5% Bio.

World wide transportation and full ethanol and how hygroscopic it can be.

 

As to the small back road independent filling station sitting with stale petrol or diesel they are very much a thing of the past.

Condensation so H20 in tanks.

Fuel is an expensive product that they pay for on delivery, then taxes, they can not afford waste, or to have to dispose of fuel, and locals buying fuel would soon know if it was 'off'.

Edited 1 August, 20196 yr by Roottootemoot

It seems very difficult to get any concrete information on UK fuels other than they meet the minimum spec. I have no idea what's in Sainsbury's fuel. Shell V power claims better cleaning additives as do some of the other super unleaded fuels. There doesn't seem to be any benefit from regularly using these expensive fuels. If they are good at cleaning the engine then surely just occasional use would do the trick ? Shell claim that one tank of v power cleans 60% of the grot out of an engine. So I might stick some in once or twice a year, but can't see any point in using it all the time.

 

I've read that TSI engines do have the potential to get coked up. Has this ever happened from regularly using non branded 95 supermarket fuels ?

They do like to say it is better than there last better fuel and better than the less expensive not Super Unleaded.

to be honest i Do a certain route every few days and it used to be about 44 mpg now im easily always over 50 usaing just regular unleaded fuel. Sadly my car still has a weird starting issue where it does not uhh.. turn over striaght away.. all the time. most of the time its 3-4 ru ru ru's sometimes its 1 a few times its been as high as 6-7 it did start better on higher octane fuel. but my consumption was defo down... such a weird car

Here is a old Honest John Article.

Things move on over the decades, only cars fuel economy has never improved that much and in some cases is worse. Maybe just less emissions, but then maybe not.

http://honestjohn.co.uk/faq/best-fuels

 

https://www.autocar.co.uk/car-news/technology/under-skin-difference-between-regular-and-super-unleaded-fuel ???

 

 

^^^ 

Strange article.

When you go into a UK filling station there is likely to be the choice of, 

95 ron Unleaded or 97 ron Super Unleaded,

or at others, 

95 ron Unleaded or 99 ron Super Unleaded.

 

So no mention of 95 ron in the article.    Just Premium and Super Unleaded.   & a mention of Regular.

 

Premium is usually what the Diesel is referred to as being for the more expensive one.

Edited 12 August, 20196 yr by Roottootemoot

Just now, Roottootemoot said:

^^^ 

Strange article.

When you go into a UK filling station there is likely to be the choice of, 

95 ron Unleaded or 97 ron Super Unleaded,

or at others, 

95 ron Unleaded or 99 ron Super Unleaded.

 

So no mention of 95 ron in the article.

I'll keep on using my Tesco Momentum 99 octane.

4 octane different from the 95 ron.

I just read the comments below the article.  (one poster says 85, that will be a typo.)

Seeing the Authors experience as a freelance writer it is a weird article as written.

Edited 12 August, 20196 yr by Roottootemoot

Changing from Shell V-Power (as I was used to with the considerably older Mx5 which had a marked decrease in smoothness on anything else) to regular 95ron from either Tesco or Shell has had no notable decrease in power with the 1.0 95ps. I'm still getting the same sort of mileage per tank, but for less cost, so I'll continue.

If not already said the higher rating reduces engine knock:

RON, or Research Octane Number, is a number that is awarded to different grades of fuel with regards to its capability to resist auto-ignition aka. knocking. Thus with higher grade RON fuels in your ride, your engine would find it more difficult to auto-ignite as resistance is higher.

http://briskoda.net/forums/topic/470749-10-tsi-remap-success