Hope this doesn't sound too daft, but I'm confused. Yeti handbook says use Super Unleaded fuel, but the sticker in the fuel flap agrees, but then says min 95 RON, which is regular fuel. Am I going to do any damage by saving 8p a litre and unsung regular?

Which Country are you in, is it the UK?

 

Your car will be fine if it is a Petrol Car on 95 RON (95 octane) 'Unleaded' Fuel if it is a petrol car.

If in the UK Tesco Momentum 99 which is 99 RON Minimum might be 5 pence a litre extra, and for £2-3 a tank extra it can pay its way.

Shell V-Power Nitro 5 pence a litre more again.

 

In the UK,

Sainsburys, Esso, BP 'Super' Unleaded are only 97 ron Minimum.

Edited 29 May, 201511 yr by goneoffSKi

Does it say "super" or "premium"? Premium unleaded is the normal, 95 RON stuff (you can get lower grades abroad).

Out in the sticks (here) 'premium' (PULP) is either 95 or 98.

Our 'standard' is 91

We've also got a 10% ethanol blend E10 which is claimed to be 100 but is on the skids it seems.

You will find that all the published performance and economy stats that are quoted have been achieved using 98Ron. In some cars there is a clear advantage both in terms of performance and economy using the higher Ron fuel. In others there is littler or no difference. As a rule of thumb, the higher state of tune for the engine, the more likely the noticeable improvements. Normally aspirated cars are also less likely to benefit.

My advice to the OP is to run a couple of tank fulls of each fuel and measure the average fuel consumption. Without a rolling road you won't really notice a power difference. You need a couple of tank fulls to allow the ECU to fully adapt to the fuel. In some cars I have had, the improvement in fuel consumption alone has 'paid' for the extra few pence a litre, in others the difference has been negligable.

It's also worth saying that the premium fuels do have a better cocktail of additives so there are additional benefits to using them. Certainly avoid supermarket fuel. They really cut back on th additives and even their 95Ron will perform worse than Shell, BP etc. A friend owns a Gulf franchise filling station. He explained how the refinery mixes the fuel to the buyers spec and how the supermarkets really skimp on them. He can't compete on price with the Tesco and Asda 2 miles away and is always a couple of pence dearer. Yet all the local taxis use him as they claim his diesel fuel gives them 3-4 MPG better so more than pays for itself.

As I said, let's not confuse "premium" with "super". In the UK, the minimum we get is "premium"; there is no universal name for the higher RON versions.

Also, it is a requirement of type approval that all cars sold in the EU are capable of running on 95 RON without problem.

The Published Performance Figures, Economy & Emissions are not given from a vehicle using Super Unleaded 98 Octane Petrol and where that idea comes from i have no idea.

*Any links to evidence of this will be more than welcome.*

 

As you will see in the Owners Manual they tell you about the Fuel Octanes.

In the VW Website you will see the Recommendation on 98 Super for the 'R' & 'GTI'

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

 

The 1.4 TSI / TFSI 132-136kw Twincharger has a Prescribed (Recommended ) 98 Super in the Filler Flap.

Only Skoda / VW / Seat / Audi never mentioned this in the Brochures or the Owners Manual.

http://skoda.co.uk/pages/fuel-consumption-statement.aspx

Edited 30 May, 201511 yr by goneoffSKi

FWIW the Australian Design Rules base all petrol consumption figures on 95.

& World Wide the figures are a Minimum, because the EU Type Approved Engines might have to run in World Regions 

in many Ambient Temperatures and at high altitudes above sea level.

 

So in the UK the VWG Engines are running on pretty safe Standard 95 RON Minimum. in temps between -15 to 32*0C which is hardly Extreme and not above 3,500 Ft.

So optimum Performance can be expected and possibly performance exceeding the Minimum that less ideal conditions mean less efficiency.

 

100 Ron & plus Fuel in parts of Europe is lovely Stuff. & 102 RON in the UK like Hiperflo 250.

But no UK Retailer Sells Super 98.  Not Esso, Sainsburys, BP Ultimate or others at the pumps.

It is Super Unleaded 97 ron Minimum .

 or Tesco Momentum 99 (99 RON Minimum) & Shell V-Power Nitro 99 Ron minimum you get.

 

As to a couple of tanks to let the ECU adapt, that is nonsence,

With the ECU in the cars we are talking about here, if you have a near empty tank, a couple of litres left,

and you put in 99 Ron (or 102 ron), you will be feeling the difference within 30 miles or so when you are running the higher Octane.

Maybe not at UK NSL's.  but with Track Use, or just on the DYNO the Engine will perform to the Octane of the Fuel.

It obviously requires a MAP / ECU that can benefit from higher Octane Fuel.

 

................

Re Additives & Detergents in Petrol.

Sodium being one. ie Common Salt.

& Super Market Fuels are often given the thumbs down without actual knowledge of the source of the fuels.

 

Tesco Momentum is produced by Greenergy, and Greenergy use Import Depots with their Partner Shell in the South.

Greenergy supply many filling station retailers such as Esso.

Supermarkets buy fuel in huge bulk and it comes from many sources, and these basically are the same sources as the Big Brands.  Lots of rubbish is talked on Brands & Franchised Retailers and fuel Quality and Additives.

Many can be a Lucky dip, but they will meet the Minimum Standards, and also the Minimum Octane.

 

Try to Google or search for the UK Spec of Shell, BP, Gulf etc.

You can find it, but not easily.

http://www.tescopfs.com/our-fuel/specifications

Edited 30 May, 201511 yr by goneoffSKi

Just to be clear, common salt is not put in fuel. Sodium can be part of any number of molecules or salts, and NaCl is not soluble in fuel and has no use in a fuel environment.

To be clear on what fuel is, it is mostly 'base fuel', which is the hydrocarbon that comes out of the refineries. The base fuel is blended to get the spec needed. Then there are usually additives added to the base fuel to modify its performance. These additives includes stability enhancers, ignition improves, antioxidants, octane improvers, detergents, foam inhibitors and so on. The additives are dosed into the base fuel at the distribution hub, as it is loaded into the road tankers for delivery to specific stations. So yes, the base fuel is often common across various petrols but the additives are not, and this is what differentiates them. So if you see a Shell tanker delivering to, say, Asda, it doesn't mean that Asda are getting Shell V-Power fuel, but they may be getting base fuel from a Shell distribution hub or Shell refinery. Or that tanker is simply doing the delivery.

Engine ECUs do not 'know' what fuel they are using. There is no sensor that can do this. However, in many cars the engine can respond to how it is working and can adapt ignition and fuel maps to accommodate differences. So if the ECU detects knocking or pinking, it can retard ignition timing to save the engine. If the ECU is sophisticated enough it can dynamically advance ignition to find the sweet spot. More advanced ignition tends to lead to improved efficiency/power, so this is how a run-of-the-mill engine can benefit from higher RON.

I am no fuels expert, but I work with some and have seen some amazing stuff about how fuels behave in the combustion chamber, at a microscopic and slow-motion level. High speed video of individual droplets emerging from injectors and how they disperse into the air stream. And how this can be affected by the fuel's formulation. And how this affects the engine's performance. And ultimately why better fuel is better.

Of course common salt is not a Royal Dutch Shell secret detergent / additive but sodium is.

(Shell V-Power Nitro might well have the RON / MON that many want in the UK, but the extra expense on the Additives 

might be something best not having & can be something that you are best to avoid using in some engines  as 

plenty have found out.  Quite a few of the Twincharger owners have found the benefit of Tesco Momentum and to avoid using Shell V-Power Nitro. Not because of it being more expensive, because of the Bore Wash Issue.)

 

I do know a little bit about the fuels in use having being using them on tuned and standard engines over a fair few years,

and the ECU's and i run a Switchable Map, and also have had a few Engines on Dynos running 

the different octane fuels with standard VWG Factory ECU's.

(all i know about Production and Distribution is what i am told from those that work in the industry.)

 

http://vitalequipment.co.uk/carless-hiperflo-racing-fuels

 

 

..........................

Not in the UK obviously, and this would never happen in the UK.....

http://www.royaldutchshellplc.com/2015/01/20/shell-fined-nearly-1-million-for-falsely-selling-green-motor-fuel

Edited 30 May, 201511 yr by goneoffSKi

My 308 has a 'stratified charge' capability and I think that's why it develops diesel torque at diesel crank speeds but running 95RON.

it seems to involve multiple micro injections per power stroke......this is our first 'triple' and, having had innumerable cars with 4/6/8 cylinders, am in awe of this engine.