E5 Petrol [please discuss]

[SillyOldDuffer]

On SillyOldDuffer Said:

On Michael Gilligan Said:

On SillyOldDuffer Said:

[…]

Michael’s car might run as usefully on E10 as it does on E5.

[…]

Please define “usefully”

… that should take you a while 🙂

MichaelG.

Glad you asked, I chose ‘usefully’ carefully!

E100, E10, E5, Leaded Petrol and Diesel all have different densities and heat values.  They aren’t one size fits all.

First fuel issue is whether the engine will run at all.  Filling a petrol car with Diesel isn’t smart!  Even worse, a diesel filled with petrol might go rather a long way before internal damage brings it to a stop.  Neither combination is useful!

Second issue is the wrong grade of fuel might cause an engine to seriously underperform.  Pinking, back-firing, catalyser damage, and power loss etc.   That the engine and fuel keep going might be useful in a ‘get me home’ situation though.  Otherwise, not acceptable.

Third issue is that the fuel underperforms in a non-critical way, such as reduced range, power, or acceleration.  E100, almost pure Ethanol, has about half the heat value of petrol, so a tankful of it will only get about half the MPG.  Shock horror, except MPG is a dubious way of measuring fuel performance.  MPG doesn’t matter if Ethanol is less than half the price of Petrol because the motorist gets more miles for his money which is useful.  However, E100 is less useful when range matters more than cost, especially aircraft!

Same cost argument applies to petrol diluted with ethanol, like E5, E10 and E30.  Although MPG is reduced, the cost per mile should be cheaper than pure petrol, and that’s useful.   Though measuring MPG made good sense when all cars used fuel of the same heat value, it’s pretty misleading in 2024.

Staying with cost, many towns and cities have started to charge for polluting vehicles, and it’s age and their ability to burn greener fuels that decide the tariff,.  Useful for Londoners to own an up-to-date E10 capable car, rather than a 1947 leaded Landrover.

Lastly, future proofing is useful!   Not so long ago, leaded petrol was available at every forecourt in the land, common as muck.  Now it’s a speciality purchase.   More recently alcohol has been added to petrol, and blends now dominate the market.   Ideally the government wants us all on E10, with E5 provided as a temporary stepping stone.   Though removing E5 isn’t being pushed hard, Michael started this topic because he was concerned buying a car today that only ran on E5 would become a problem.  It will.    When E5 is taken off the market, the ability of a vehicle to run on E10 will be ‘useful‘, even if performance drops a bit.

Dave

 

 

Not sure about a 1947 Landy but think it’s exempt from London ULEZ charges due to its age, I quote “All vehicles built before 1 January 1973”.

My 2015 diesel is not exempt but an older polluter might well be, Strange logic or what!

[SillyOldDuffer]

On SillyOldDuffer Said:

[…] Michael started this topic because he was concerned buying a car today that only ran on E5 would become a problem.  […]

An excellent try, Dave … and most of your points are valid, except for that fundamental one.

Please read my opening post carefully

MichaelG.

.

Edit: [for convenient reference ] __ I wrote:

… so in the present market I will continue to use E5 ‘super unleaded’ just as I currently do.

[Graham TitmanParticipant @grahamtitman81812]

My previous vehicle a 69 plate Toyota Rav4 when i got it after a couple of thousand miles it did 53 to 54 mpg when E10 came onto the market i swapped because it was cheaper over the next 1000 mile fuel consumption went down to 44 to 45 mpg at that point i went back to using E5 petrol and the fuel consumpton went slowly back to the low 50s but it never got as high as it stared out .All my bikes i run on E5 and yesterday september 1st we paid £1 -69 A litre.

[VicParticipant @vic]

I use this quite a bit as my LPS is Shell. I didn’t know about this though.

https://youtu.be/Wp9MzzW0hs0?si=gu59YZjg0QbG27PU

 

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