E5 Petrol [please discuss]

[Michael GilliganParticipant @michaelgilligan61133]

In case anyone is interested …

I bought the Suzuki on 21-August, and Yes RON 95 Petrol is specified.

The instruments predicted a remaining Range of 25 miles, so I added £40 of BP regular unleaded E10 and drove it home from Sheffield to North Wales, and have since driven it on local trips … everything seems fine, given that it is a 10year old 4×4 with a 4-cylinder engine.

Yesterday, the Low-Fuel warning ‘chimed’ at me, so I diverted to the Tesco garage and added £50 of Momentum E5

Today … the improvement is obvious

1. Idling at the traffic-lights is almost silent
2. Pick-up from idle is smoother
3. The gear-change is smoother
4. [it’s too soon to tell, but] the mpg is looking better

These are similar to the improvements I found on the BMW, and l think it supports what I said earlier about properly implemented VVT … the engines will ‘cope-with’ low grade fuel, but are capable of getting the best out of the good stuff.

So far, I’m a Happy Bunny

Time will tell whether E5 remains available/affordable

MichaelG.

[VicParticipant @vic]

If this happens I’ll have to think about going back to E10.

[Nick WheelerParticipant @nickwheeler]

A 1.8 GDI Mitsubishi Galant is the only car I’ve owned that ever showed a barely noticeable difference when using 98Ron petrol instead of 95. The small increase in fuel economy didn’t make up for the extra cost, and the tiny improvement in power only showed when I tried using it like the 525BMW(3 occupants, loaded with stuff and booze at 100mph on the autoroute) that preceded it. Even then, lowering my expectations was the short term solution until I replaced it with a more suitable V6 Omega. All three cars were estates, and you can get a lot of stuff in a Galant or Omega.

The 1500 Avenger(single carb, 3 speed auto, very slow) I also owned at the time would run just as well on a 70/30 petrol diesel mix from draining misfueled diesels, although it did smoke a bit more…

[Vic]

On Vic Said:

If this happens I’ll have to think about going back to E10.

10P per litre increase would add an extra 4.00 Quid to my fortnightly 40 litre fill-up in my 1.8L Toyota Corolla 4 cyl. Hardly enough to lose sleep over. The price of one cup of coffee at a cafe per fortnight.

[Michael Gilligan]

On Michael Gilligan Said:

In case anyone is interested …

I bought the Suzuki on 21-August, and Yes RON 95 Petrol is specified.

The instruments predicted a remaining Range of 25 miles, so I added £40 of BP regular unleaded E10 and drove it home from Sheffield to North Wales, and have since driven it on local trips … everything seems fine, given that it is a 10year old 4×4 with a 4-cylinder engine.

Yesterday, the Low-Fuel warning ‘chimed’ at me, so I diverted to the Tesco garage and added £50 of Momentum E5

Today … the improvement is obvious

1. Idling at the traffic-lights is almost silent
2. Pick-up from idle is smoother
3. The gear-change is smoother
4. [it’s too soon to tell, but] the mpg is looking better

These are similar to the improvements I found on the BMW, and l think it supports what I said earlier about properly implemented VVT … the engines will ‘cope-with’ low grade fuel, but are capable of getting the best out of the good stuff.

So far, I’m a Happy Bunny

Time will tell whether E5 remains available/affordable

MichaelG.

Good to hear the new car is working well for you.

Of course your observations so far are highly subjective on small degees of difference, but my own one and only experience with E10 would bear it out. But that was with a classic Harley travelling across country where I was forced to use E10 in a region where nothing else was available. Service stations in the wheat belt were proudly supporting local farmers by selling nothing other than “biofuel” aka E10.

The old Harley did not want to start (arduous on kickstart only bike) and when it eventually did, would not idle at all, misfired badly, ran rough as a hairy goat at low rpm, surged and generally behaved like a secondhand lawnmower. Absolutely awful. The engine was running so hot and making so much clattering noise I thought it had loosened a valve seat insert. I managed to limp on (literally after all the kickstarting) for the next 250 miles on several tanks of this terrible stuff until I reached civilisation where I could fill up with regular 95 octane non-ethanol fuel and hey presto, the bike performed flawlessly again.

Not directly relevant to a modern car engine with better combustion chamber design. The old Harley is 9.5 to 1 hemispheric head with two valves at 45 degree angles each and high-top domed pistons  with sparkplug at one side. Almost the worst design for detonation. But it did show me conclusively that E10 does not burn the same as non-ethanol fuel.

And the thing about ethanol bio-fuel reducing carbon footprint etc, I have read that the production of the nitrogen fertiliser used to grow the grain to make the ethanol creates more carbon than if the vehicles just burned straight non-ethanol fuel.

And so the world goes round and round.

[Hopper]

On Hopper Said:

On Vic Said:

If this happens I’ll have to think about going back to E10.

10P per litre increase would add an extra 4.00 Quid to my fortnightly 40 litre fill-up in my 1.8L Toyota Corolla 4 cyl. Hardly enough to lose sleep over. The price of one cup of coffee at a cafe per fortnight.

A typical “I’m all right Jack response”.

[Vic]

On Vic Said:

On Hopper Said:

On Vic Said:

If this happens I’ll have to think about going back to E10.

10P per litre increase would add an extra 4.00 Quid to my fortnightly 40 litre fill-up in my 1.8L Toyota Corolla 4 cyl. Hardly enough to lose sleep over. The price of one cup of coffee at a cafe per fortnight.

A typical “I’m all right Jack response”.

I was merely following your heading on the thread “PLEASE DISCUSS” and relating my personal experience in a polite manner.

Discussion does not consist of gratuitous derogatory comments such as yours. That might be perceived as trolling.

 

[Michael Gilligan]

On Michael Gilligan Said:

1. …

These are similar to the improvements I found on the BMW, and l think it supports what I said earlier about properly implemented VVT … the engines will ‘cope-with’ low grade fuel, but are capable of getting the best out of the good stuff.

So far, I’m a Happy Bunny

Time will tell whether E5 remains available/affordable

MichaelG.

PS the other thing is, your Suzuki’s knock sensor would almost certainly retard the ignition timing if it sensed detonation with with the E10, which would definitely affect performance. Whether it would affect the VVT I am not sure. Quite possibly but most VVT is either on or off, perhaps through a narrow range, kicking in at a pre-set RPM usually up around 3 or 4,000 RPM. All it does on the Suzi is increase the duration of the inlet valve opening at higher RPM, thus allowing better cylinder filling, while the shorter duration at lower RPM reduces overlap and enhances low speed running. So you would not expect it to be any influence at idle or low speed pick up off idle. More likely the ignition timing methinks, but with today’s complex engine control systems, who knows? Fuel injection could be affected too.

[Hopper]

On Hopper Said:

Good to hear the new car is working well for you.

Of course your observations so far are highly subjective on small degees of difference, but my own one and only experience with E10 would bear it out. But that was with a classic Harley travelling across country where I was forced to use E10 in a region where nothing else was available. Service stations in the wheat belt were proudly supporting local farmers by selling nothing other than “biofuel” aka E10.

The old Harley did not want to start (arduous on kickstart only bike) and when it eventually did, would not idle at all, misfired badly, ran rough as a hairy goat at low rpm, surged and generally behaved like a secondhand lawnmower. Absolutely awful. The engine was running so hot and making so much clattering noise I thought it had loosened a valve seat insert. I managed to limp on (literally after all the kickstarting) for the next 250 miles on several tanks of this terrible stuff until I reached civilisation where I could fill up with regular 95 octane non-ethanol fuel and hey presto, the bike performed flawlessly again.

[…]
But it did show me conclusively that E10 does not burn the same as non-ethanol fuel.

[…]

Thanks for the observations, Hopper … much appreciated.

it’s interesting [but very predictable] to see how the issue manifests itself ‘from the opposite perspective’

I’m quite sure that both car engines would respond in a similarly cantankerous manner to your Harley, if were not for the ‘modern miracle’ of VVT, which cleverly masks the worst effects of bad fuel by actively re-tuning the engine to accommodate it.

… Your Harley, lovingly tuned by its sympathetic rider, has no such mechanism; and therefore exposes the hideous reality !

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

For any onlookers, who might not understand … here is a good description of BMW’s VANOS system:

https://m3list.com/what-does-vanos-stand-for-what-are-the-symptoms-and-how-does-it-work/

… it’s not exclusive to the M3, it’s an E46 thing.

MichaelG.

[Michael Gilligan]

On Michael Gilligan Said:

On Hopper Said:

Good to hear the new car is working well for you.

Of course your observations so far are highly subjective on small degees of difference, but my own one and only experience with E10 would bear it out. But that was with a classic Harley travelling across country where I was forced to use E10 in a region where nothing else was available. Service stations in the wheat belt were proudly supporting local farmers by selling nothing other than “biofuel” aka E10.

The old Harley did not want to start (arduous on kickstart only bike) and when it eventually did, would not idle at all, misfired badly, ran rough as a hairy goat at low rpm, surged and generally behaved like a secondhand lawnmower. Absolutely awful. The engine was running so hot and making so much clattering noise I thought it had loosened a valve seat insert. I managed to limp on (literally after all the kickstarting) for the next 250 miles on several tanks of this terrible stuff until I reached civilisation where I could fill up with regular 95 octane non-ethanol fuel and hey presto, the bike performed flawlessly again.

[…]
But it did show me conclusively that E10 does not burn the same as non-ethanol fuel.

[…]

Thanks for the observations, Hopper … much appreciated.

it’s interesting [but very predictable] to see how the issue manifests itself ‘from the opposite perspective’

I’m quite sure that both car engines would respond in a similarly cantankerous manner to your Harley, if were not for the ‘modern miracle’ of VVT, which cleverly masks the worst effects of bad fuel by actively re-tuning the engine to accommodate it.

… Your Harley, lovingly tuned by its sympathetic rider, has no such mechanism; and therefore exposes the hideous reality !

MichaelG.

At the heart of it is the  very outdated combustion chamber design as described. The charge is compressed into a crescent shaped sliver betwixt high piston dome and hemispherical combustion chamber. The spark plug is located at one end of that crescent. So it ignites the charge at that end and the flame front has to travel up and over the high piston top and down the other side. The last little bit of unburned fuel mix is compressed between the end of the crescent and the advancing flame front, so spontaneously combusts and goes “PING”.

Plus no knock sensors to retard ignition timing.

Modern cars have a shallow combustion chamber designed to minimise this. As do modern Harleys, which will run on much lower octane fuel than the older ones, and E10,  thanks to compact “bathtub” combustion chambers, flatter valve angles and squish bands. No VVT on the Harleys to date.

[Robert Atkinson 2Participant @robertatkinson2]

It’s not just VVT that compensates for fuel differences. Not all engines have it. Modern ECUs maeasure lots of parameters and may adjust ignition timing, mixture, boost pressure, fuel timing and valve timing as appropriate / available. Most ECUs keep a list of “learned” parameters. It can be useful and interesting to reset these after any change such as critical component replacement or fuel change.

Robert.

[Michael Gilligan]

On Michael Gilligan Said:

…
The instruments predicted a remaining Range of 25 miles, so I added £40 of BP regular unleaded E10 and drove it home from Sheffield to North Wales, and have since driven it on local trips … everything seems fine, given that it is a 10year old 4×4 with a 4-cylinder engine.

Yesterday, the Low-Fuel warning ‘chimed’ at me, so I diverted to the Tesco garage and added £50 of Momentum E5

Today … the improvement is obvious

1. Idling at the traffic-lights is almost silent
2. Pick-up from idle is smoother
3. The gear-change is smoother
4. [it’s too soon to tell, but] the mpg is looking better

These are similar to the improvements I found on the BMW, and l think it supports what I said earlier about properly implemented VVT … the engines will ‘cope-with’ low grade fuel, but are capable of getting the best out of the good stuff.

So far, I’m a Happy Bunny

Time will tell whether E5 remains available/affordable

MichaelG.

I hope Michael won’t be offended if I point out his results are untrustworthy because the experiment is flawed.  Not possible to draw any conclusions yet, other than the car ‘goes OK’.

Problems include:

• A sample of one is far too small, especially over such a short time and distance.
• The results aren’t measured.  Subjective opinion always has high risk of observer bias, and is particularly likely when there is only one observer.
• Of the ‘improvements’ only MPH is measurable, and that hasn’t been done yet.   Not quick or easy.  Drive the car for 6 months on E5 and then compare the result with driving 6 months on E10.   Same type of journey in both cases.    And MPH may not be the correct measure:  cost per mile, or kg CO2 per km might be more appropriate.
• Even if Michael’s observations are accurate they can be explained by other than the change of fuel:
  • The car may have been off the road for some time before Michael drove it home, causing the mechanicals to stiffen.  Maybe the journey home fixed this by heating the engine, shifting gummed oil, stirring the cooling system, taking the set out of belts and tyres, cleaning plugs, and exercising the transmission etc.   The improvements may be due to the drive home, not the fuel – remember ‘Italian Tune-ups’
  • The car was run home almost on empty which tends to concentrate the amount of dirt in the fuel.  Completely filling the tank with fresh fuel stirs and dilutes dirt, and the engine runs better.

Whilst true that engines not designed for a particular grade of fuel are likely to gag on it, it’s dangerous to generalise.   Older engines manage fuel and timing with relatively crude mechanical devices that can’t cover a wide range of operating conditions.   Modern engines have more sensors and an electronic management system that can change timing and fuel mix on the fly making them less fussy than old bangers.

Engineers shouldn’t jump to conclusions!  Michael’s car might run as usefully on E10 as it does on E5.  I look forward to more reports, but at the moment no one knows.

Dave

[Bob WorsleyParticipant @bobworsley31976]

I had an old Range Rover classic, V8, and wouldn’t run on E10. I bought the ESSO Synergy Supreme +99 which is ethanol free.

Run ok? I would say, from E5 it upped the miles per tank from around 270 to 350, amazing.

Apparently any older engine, more than 10 years or so, for brush cutters, generators etc etc will run far better on the zero ethanol mix.

 

[Robert Atkinson 2]

On Robert Atkinson 2 Said:

It’s not just VVT that compensates for fuel differences. Not all engines have it. Modern ECUs maeasure lots of parameters and may adjust ignition timing, mixture, boost pressure, fuel timing and valve timing as appropriate / available. Most ECUs keep a list of “learned” parameters. It can be useful and interesting to reset these after any change such as critical component replacement or fuel change.

Robert.

Thanks for the elaboration, Robert

I admit to gross oversimplification … mostly because the detail of the system is beyond my comprehension !
The electronic wizardry is largely a ‘black box’ to me, so I singled-out the VVT as a magnificent example of mechanical engineering.

I could only describe this stuff in the “arm-waving” way that Astronomers describe the Universe, and that would do little to advance the discussion !

Please keep the discussion going : I know, from ‘seat of the pants’ evidence, that three cars of mine [with sophisticated engine-management] have all demonstrated the superiority of E5, and Hopper’s story serves beautifully to show how ugly the underlying reality can be.

How much technology is it appropriate to chuck-into the mix, to compensate for poor fuel … I wonder ???

MichaelG.

[SillyOldDuffer]

On SillyOldDuffer Said:

[…]  I hope Michael won’t be offended if I point out his results are untrustworthy because the experiment is flawed.  […]

Not at all, Dave … I would not expect anything less from you.

MichaelG.

[SillyOldDuffer]

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.

[NealebParticipant @nealeb]

For reasons that are explained below, this contribution harks back to my days before retirement and regularly commuting by motorbike. I kept detailed fuel bought/miles covered records, and maintained a spreadsheet to collate the data with graphs showing both “tank-by-tank” and “averaged” consumption. The averaged values were derived from a weighted mean of the previous “average” value and the latest “instaneous” value with weightings of 90/10 (from memory – on holiday at the moment and I do not have the data with me). The weighting was also modified by the proportion of a tankful added. I felt that the averaged values actually held some useful information where the instantaneous values by themselves were pretty pointless. The problem was that although my riding style was more-or-less constant – I’m a bit of a wimp on the bike and think more about fuel consumption than performance – and the journeys fairly consistent, the tank-to-tank values varied wildly. With a rough average of, say, 48-50mpg, I could see successive tank consumptions variation of 4-6mpg and sometimes more. Same fuel (it happened that I usually filled at the same garage every couple of days), same route, etc. But wind, rain, traffic, temperature, and probably a bunch of other variables all introduce random factors. Also leads me to believe that anyone asking for “real world” fuel consumption values for comparison purposes doesn’t know what they are talking about, but that’s by-the-by.

However, the average figures did show that there was a real difference between summer and winter consumption with a defined seasonal variation, but that was of the order of 2-3mpg and so hidden in the noise without averaging. There was one time when the consumption seemed to be taking a significant turn for the worse – turned out to be that I had forgotten an air filter clean which restored the status quo.

By the same token, I found that my bike was faster if I had a tank bag fitted than when it did not. Eventually I realised that it was because it modified the airflow over the bike and there was a little more wind noise. In fact, it sounded faster! Hence, as well as having little confidence in so-called “real-world” measurements which do not define exactly which real world they are in, I have less confidence in subjective “it’s running lots better” comments without knowing the credentials of the speaker (and I do believe that some highly-experienced drivers can do this but I doubt that there are many). Come back in 5000miles time with careful objective measurements and let’s see!

I can’t give any data from more recent driving/biking as having retired, my journeys are random and highly variable. No consistency. All I can say is that anecdotally (i.e. not backed up by careful measurement) over the years the various Audis I have driven seem to give slightly better fuel consumption above about 15C than below to the extent that I wonder if this is actually some artefact of the engine management system.

So, please, can I make a plea for reports to be backed up by objective measurements, obtained under, as far as possible, controlled conditions? In my own car, one tankful could achieve around 35mpg if it was used for local pottering about and the next 50mpg if it was a long distance motorway trip. And please, do not talk about fuel consumption in terms of cost of filling a tank! Means a lot to you but zilch to the rest of the world…

[Nick WheelerParticipant @nickwheeler]

I was wondering why Michael picked VVT as the main beneficiary of ‘better’ fuel. VVT(whatever type) is used to extend/ tailor the engine’s powerband/delivery – a high performance engine can use it to improve low down power, or commuter car can benefit from VVT on the rare occasions it’s revved hard. The mechanics of them is clever though.

 

The real improvement is full control of fuelling and ignition. This is easily proved if you compare the same engine with and without it – fitting an injected Ford Pinto in place of a carb one gives more power, better drivability, improved durability and economy. Mapped ignition adds significant improvements when added to old engines while retaining the carburettor and is relatively cheap and easy to do.

[Nick Wheeler]

On Nick Wheeler Said:

I was wondering why Michael picked VVT as the main beneficiary of ‘better’ fuel. VVT(whatever type) is used to extend/ tailor the engine’s powerband/delivery – a high performance engine can use it to improve low down power, or commuter car can benefit from VVT on the rare occasions it’s revved hard. The mechanics of them is clever though.

 

[…]

Mea Culpa !!

I hope I have already explained, in my reply to Robert

… I am honestly more interested in the fact that [whilst not actively investigating anything] I noticed the improvements listed during a short journey of 22 miles round-trip.

The better idling-behaviour at the traffic lights was astonishingly obvious … I had to look at the rev-counter to check that the engine was running!

Previously there had been a slight ‘trembling’ noticeable, which I had attributed to the Suzuki only having a four cylinder engine.

I make no claims of scientific rigour here …

MichaelG.

[Nealeb]

On Nealeb Said:

[…]  And please, do not talk about fuel consumption in terms of cost of filling a tank! Means a lot to you but zilch to the rest of the world…

I wasn’t, Neal … but I accept the validity of your point

£40.20 of BP E10 unleaded = 28.33 litres

£50.00 of Tesco Momentum E5 unleaded = 34.04 litres

MichaelG.

.

It is pointless for me to report the previous average figures for mph and mpg because I have no evidence of the driving conditions, but …

Having zeroed both at the month-end, I will report my figures for September in due course. … That’s as technical as it will get.

MichaelG.

[HopperParticipant @hopper]

..<br class=”bsp-quote-title” />So, please, can I make a plea for reports to be backed up by objective measurements, obtained under, as far as possible, controlled conditions?

If that ever happened, the internet would be silent. 🙂

[V8EngParticipant @v8eng]

To diversify a little:

Perhaps questions also should be asked about the sources of vast quantities of ethanol or methanol (whichever it is) used in all the consuming countries.

[Michael Gilligan]

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

 

 

[duncan webster 1Participant @duncanwebster1]

Whether it’s E5 or E10, a chap who worked at Thornton Research Centre advised me that every 3rd thankful you should buy branded (ie non supermarket) fuel. The actual petrol is exactly the same but the branded stuff has additives which protect amongst other things your lambda sensor. Same advice from my local garagiste.

Back on track, I pointed out before that ethanol is known to be a knock suppressant. If this is true, a lot of the previous postings have been barking up the wrong tree.

[Author]

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