Petrol differentials

MiniOwner

What is a fair difference to pay for super unleaded petrol. The service stations advertise the price of ordinary unleaded but you don't know the price of super until you are at the pump. I've paid 7p extra at Tesco and 19p extra at Morrisons!

eskbanker

MiniOwner said:

you don't know the price of super until you are at the pump

You can research prices for all fuel types online at the likes of PetrolPrices:

Find The Cheapest Fuel Near Me Today | PetrolPrices.com

Rodders53

Pricing is a Commercial decision of the fuel station operators.

Use something like Find The Cheapest Fuel Near Me Today | PetrolPrices.com to seek out the best price local to you.  They can occasionally be wrong, but not that often.

But virtually no modern vehicle needs Super Unleaded, as I understand it.  So the MSE thing would be to use E10 95 RON fuel, rather than 98 RON E5;  unless you have an older vehicle that requires super unleaded..

Typhoon2000

7p is a pretty good difference between E5 and E10 at current fuel prices. The additional energy density of E5 is basically covered by the cost ( the higher mpg you get will cover the price difference), so the higher octane ( even if your car advance engine timing to benefit ) and additives is basically free. 

SiliconChip

Typhoon2000 said:

7p is a pretty good difference between E5 and E10 at current fuel prices. The additional energy density of E5 is basically covered by the cost ( the higher mpg you get will cover the price difference), so the higher octane ( even if your car advance engine timing to benefit ) and additives is basically free. 

Do you have a reference for the part that I've bolded? I found a Wikipedia article that describes a study done in Finland in 2011 that found E5 to improve consumption by about 1% over E10, if that's correct it would cover a price difference of less than 2p per litre, which is well below the actual price difference.

https://en.wikipedia.org/wiki/Common_ethanol_fuel_mixtures 

A 2011 study conducted by VTT Technical Research Centre of Finland found practically no difference in fuel consumption in normal driving conditions between commercial gasoline grades 95E10 and 98E5 sold in Finland, despite the public perception that fuel consumption is significantly higher with 95E10. VTT performed the comparison test under controlled laboratory conditions and their measurements showed that over a distance of 100 kilometres (62 mi), the cars tested used an average of 10.30 litres (2.27 imp gal; 2.72 US gal) of 95E10, as opposed to 10.23 litres (2.25 imp gal; 2.70 US gal) of 98E5. The difference was 0.07 in favor of 98E5 on average, meaning that using 95E10 gasoline, which has a higher ethanol content, increases consumption by 0.7%. When the measurements are normalized, the difference becomes 1.0%, a result that is highly consistent with an estimation of calorific values based on approximate fuel composition, which came out at 1.1% in favour of E5.

Typhoon2000

Here are a couple
https://www.rac.co.uk/drive/advice/emissions/what-is-e10-fuel-and-how-could-it-affect-you/
https://www.thetimes.com/money-mentor/income-budgeting/cost-of-living-crisis/is-e5-petrol-more-economical-than-e10

HillStreetBlues

Tesco always seems to be cheaper for me for SL

LightFlare

SiliconChip said:

Typhoon2000 said:

7p is a pretty good difference between E5 and E10 at current fuel prices. The additional energy density of E5 is basically covered by the cost ( the higher mpg you get will cover the price difference), so the higher octane ( even if your car advance engine timing to benefit ) and additives is basically free. 

Do you have a reference for the part that I've bolded? I found a Wikipedia article that describes a study done in Finland in 2011 that found E5 to improve consumption by about 1% over E10, if that's correct it would cover a price difference of less than 2p per litre, which is well below the actual price difference.

https://en.wikipedia.org/wiki/Common_ethanol_fuel_mixtures 

A 2011 study conducted by VTT Technical Research Centre of Finland found practically no difference in fuel consumption in normal driving conditions between commercial gasoline grades 95E10 and 98E5 sold in Finland, despite the public perception that fuel consumption is significantly higher with 95E10. VTT performed the comparison test under controlled laboratory conditions and their measurements showed that over a distance of 100 kilometres (62 mi), the cars tested used an average of 10.30 litres (2.27 imp gal; 2.72 US gal) of 95E10, as opposed to 10.23 litres (2.25 imp gal; 2.70 US gal) of 98E5. The difference was 0.07 in favor of 98E5 on average, meaning that using 95E10 gasoline, which has a higher ethanol content, increases consumption by 0.7%. When the measurements are normalized, the difference becomes 1.0%, a result that is highly consistent with an estimation of calorific values based on approximate fuel composition, which came out at 1.1% in favour of E5.

Whilst not conclusive evidence - my previous car when doing a long motorway run would get ~10% gain in economy using “premium” over none premium.

As has been stated many times - it’s very case specific and won’t apply to the majority of vehicles (did t 5th gear do something about it many years ago)

facade

Most of us who won't let e10 near our cars are not doing it for economy reasons.

I've seen what ethanol fuel does to some plastic fuel system components, and my car had a new fuel pump on recall because it was made of the wrong type of plastic and might swell up and jam with e10.

I just put £10 or £20 worth in at a time (after many years I discovered that button on the pump that pre-sets it to dispense £10), and never worry about the actual price per litre.

I always keep the receipt in case of fuel contamination, and only pay cash after co-incidentally having fraudulent bank charges appear shortly after using a "pay at pump" machine once. (seemed the most likely source though, I bought petrol early in the morning, anything could have been done to the pump overnight when the station was closed)

SiliconChip

Typhoon2000 said:

Here are a couple
https://www.rac.co.uk/drive/advice/emissions/what-is-e10-fuel-and-how-could-it-affect-you/
https://www.thetimes.com/money-mentor/income-budgeting/cost-of-living-crisis/is-e5-petrol-more-economical-than-e10

I can't see anything in either article that confirms that improved consumption figures for E5 offset the additional cost over E10. While they suggest better figures than the Finnish study (without going into much detail on how the figures were obtained) the best improvement mentioned is 4% which might just about cover the 7p difference mentioned but wouldn't come anywhere near the 19p difference also mentioned, and while I don't look at E5 prices I suspect that 7p is very much at the lower end and at many filling stations the difference is more.

Typhoon2000

Yes I find the Tesco momentum 99 to typically be 7p more expensive in all stations I have come across outside London ( where I have found some to be 10p). I don’t fill up Super unleaded anywhere else. Sainsbury used to be 7 p more but seem to have moved up to 10p ( and also it 97Ron rather than 99). My car does adjust for higher octane by detecting the lack of knock increasing the timing and producing more power, which means lower revs needed for any given speed and even more MPG. A 7p at current prices I am better off. When the cost of unleaded was higher there was even more savings.