General What fuel do you put in your petrol 500?

[Muz R]

I have only owned mine for just over a month. It’s a 59 1.4 and I have put E5 in whenever I have filled it up. Am I throwing my money away? Old School here and I am reluctant to put E10 in either of my cars as I fear it’s more planet saving than as good as E5 for the engine.

Educate me

 

[John202020]

We have a 09 plate 1.2 500 and a 07 plate 2L Mazda 6 both get E10 without issue usually Esso but sometimes Morrisons as its the cheapest around £1.37 petrol or Diesel

 

[z rider]

I don't know if Fiat recommends E10, I used it in my Cinquecento Sporting. As far as my Twiair is concerned I use E5, and will not use E10. I havent tried Super Plus or Ultimate as I think the car doesn't need it. Owners handbook states 95 ROZ but gives no hint to E10. My car is 2012.

 

[Pugglt Auld Jock]

I think there are two main issues with E10. One is the compatibility issue which is to say that for any particular vehicle will the fueling system be affected negatively by the corrosive nature of E10 - fuel pipes, seals and the like. You can easily check that out here: https://www.gov.uk/check-vehicle-e10-petrol

The other is that you are likely to get less MPG using E10 as it's slightly less energy dense. Oh, and E10 will absorb more water vapour so if the vehicle is likely to lie up unused for periods of time I'd be using E5 to lessen the likelyhood of water collecting in the bottom of the tank (you can buy fuel conditioners which combat this). For this reason I use E5 in my old Horticultural machines.

For better or worse we tend to fill up at either Morrisons or Asda with E10 which we started using in both the cars as it was introduced. Can't really say I've noticed any significant difference in the way either vehicle drives - 2010 Panda 1.2 Eco Dynamic and 2016 Ibiza 1.0 litre 3 cylinder turbo ecomotive.

I would not expect the 60hp FIRE engine in the Panda to be able to make any better use of a higher octane fuel than it does of the 95 RON E10 but I've sometimes wondered if the Ibiza with it's turbo and sophisticated ignition system - needed to control knock with the use of the turbo - might produce more power and better fuel consumption on 97/98 RON E5. So, back in the spring when we went on our "Devon Odyssey" I let her run out to nearly empty just prior to leaving and filled her to the second click with Shell V power E5. A tankful just gets us there so next day I filled up to the second click off (my usual procedure) and worked out the consumption. Over the last 5 times we've done this journey in this car she's consistently returned between 58.5 and 60 Miles Per Gallon for the whole journey. I was slightly disappointed to find she was right on the 60mpg this time - measured not by the onboard computer (although, on longer journeys it's really very accurate) but from full tank (2 clicks on a level forecourt in Edinburgh) to full tank (2 clicks on a level forecourt at Tesco in Barnstaple). So, in my experience and as a result of my unscientific observation, The considerably more expensive higher octane E5 produced the same driving dynamic and fuel consumption as the 95 RON supermarket fuel. Which is not to say that the superior additive package in the higher octane fuel maybe benefited the engine in other ways which the E10 couldn't?

 

[Muz R]

It was what I’ve read about the potentially corrosive nature on engine ancillaries that has put me off E10, not concerned about 1-2% better fuel figures E5 may give. OK it’s more expensive but mileage is just local trips.

 

[Pugglt Auld Jock]

It was what I’ve read about the potentially corrosive nature on engine ancillaries that has put me off E10, not concerned about 1-2% better fuel figures E5 may give. OK it’s more expensive but mileage is just local trips.

Before the Ibiza I've owned cars with largish capacity, "lazy" engines and kept them until they became "beyond economic repair". Now, with these small turbo, very high pressure and complex direct injection fuel systems on relatively highly stressed engines and pretty lightweight construction of many components I don't think keeping these cars for maybe 15 to 20 years makes any sense. I'm certainly not expecting the Ibiza to be a "keeper" like my previous 1.9 tdi Cordoba was so I'm not so concerned about these long term component corrosion aspects. The problem then becomes, what am I going to replace it with?

 

[chris3234]

I think there are two main issues with E10. One is the compatibility issue which is to say that for any particular vehicle will the fueling system be affected negatively by the corrosive nature of E10 - fuel pipes, seals and the like. You can easily check that out here: https://www.gov.uk/check-vehicle-e10-petrol

The other is that you are likely to get less MPG using E10 as it's slightly less energy dense. Oh, and E10 will absorb more water vapour so if the vehicle is likely to lie up unused for periods of time I'd be using E5 to lessen the likelyhood of water collecting in the bottom of the tank (you can buy fuel conditioners which combat this). For this reason I use E5 in my old Horticultural machines.

For better or worse we tend to fill up at either Morrisons or Asda with E10 which we started using in both the cars as it was introduced. Can't really say I've noticed any significant difference in the way either vehicle drives - 2010 Panda 1.2 Eco Dynamic and 2016 Ibiza 1.0 litre 3 cylinder turbo ecomotive.

I would not expect the 60hp FIRE engine in the Panda to be able to make any better use of a higher octane fuel than it does of the 95 RON E10 but I've sometimes wondered if the Ibiza with it's turbo and sophisticated ignition system - needed to control knock with the use of the turbo - might produce more power and better fuel consumption on 97/98 RON E5. So, back in the spring when we went on our "Devon Odyssey" I let her run out to nearly empty just prior to leaving and filled her to the second click with Shell V power E5. A tankful just gets us there so next day I filled up to the second click off (my usual procedure) and worked out the consumption. Over the last 5 times we've done this journey in this car she's consistently returned between 58.5 and 60 Miles Per Gallon for the whole journey. I was slightly disappointed to find she was right on the 60mpg this time - measured not by the onboard computer (although, on longer journeys it's really very accurate) but from full tank (2 clicks on a level forecourt in Edinburgh) to full tank (2 clicks on a level forecourt at Tesco in Barnstaple). So, in my experience and as a result of my unscientific observation, The considerably more expensive higher octane E5 produced the same driving dynamic and fuel consumption as the 95 RON supermarket fuel. Which is not to say that the superior additive package in the higher octane fuel maybe benefited the engine in other ways which the E10 couldn't?

It is often said it takes around 3 tank full of the higher octane fuel for most cars to adjust to it



That being said I've tired that befor and never found any difference
So it may not be true

 

[Piccolo Nero e Bella]

May not be relevant but I've run my Twinair on 98RON since I got it in 2013. Australian fuels are said to be of lower quality generally compared to those available overseas so it seemed the safe course. It costs more but with the low mileage I stack up these days (20-25 miles/week) that's not really an issue. It's supposed to have zero ethanol but who really knows what's in the liquid you pump into the tank at the bowser?

 

[Lounge lizard]

E5 for my wife's 2011 T/A as it does not get used that much. I have done the odd fill of E10 when E5 hasn't been available.
Generally the premium/higher octane stuff is E5 and as the T/A doesn't have a fuel filter I think I'll carry on.

 

[DaveMcT]

I have a 1.4 Panda 100HP which has run happily on Tesco 99 Posh for the last 50,000 miles. It runs on vanilla 95 but feels like the exhaust is blocked and uses considerably more fuel. The posh is more money per litre but cost per mile is probably much the same and the car is so much nicer to use.

My BMW 1200 bike absolutely hated 95. Fuel consumption was considerably worse, it stalled at junctions and exhaust pipes would glow red at night. No surprise, the knock sensor retards spark timing so more heat gets lost down the exhaust.

 

[Muz R]

I have a 1.4 Panda 100HP which has run happily on Tesco 99 Posh for the last 50,000 miles. It runs on vanilla 95 but feels like the exhaust is blocked and uses considerably more fuel. The posh is more money per litre but cost per mile is probably much the same and the car is so much nicer to use.

My BMW 1200 bike absolutely hated 95. Fuel consumption was considerably worse, it stalled at junctions and exhaust pipes would glow red at night. No surprise, the knock sensor retards spark timing so more heat gets lost down the exhaust.

Interesting, I didn’t know 99 was still available. Certainly not in the petrol stations around me, just E10 or E5 but I haven’t checked Tesco. I will check it out

 

[DaveMcT]

The manufacturer's power and mpg specifications are done using 97 RON fuel which is about equivalent to the old 4 star leaded. All modern engine will safely use lower octanes but fuel consumption suffers. It's kept quiet because government makes more tax and Big Oil sells more petrol

 

[John202020]

Interesting, I didn’t know 99 was still available. Certainly not in the petrol stations around me, just E10 or E5 but I haven’t checked Tesco. I will check it out

E5 is usually a minimum of 97 often higher

 

[Muz R]

I have a 1.4 Panda 100HP which has run happily on Tesco 99 Posh for the last 50,000 miles. It runs on vanilla 95 but feels like the exhaust is blocked and uses considerably more fuel. The posh is more money per litre but cost per mile is probably much the same and the car is so much nicer to use.

My BMW 1200 bike absolutely hated 95. Fuel consumption was considerably worse, it stalled at junctions and exhaust pipes would glow red at night. No surprise, the knock sensor retards spark timing so more heat gets lost down the exhaust.

Seems you are not alone in your thoughts!,

 

[Pugglt Auld Jock]

Seems you are not alone in your thoughts!,

Hmm. Plenty of food for thought there. Of course they are running an engine which is set up to most effectively use the higher octane fuel. I'm just wondering if a standard fuel/ignition map has enough leeway to really effectively use a higher octane fuel? I presume the ignition will keep on chucking in more advance until it "hears" some pinking so maybe the ignition can do it. I'm not so clear about fueling though - be interesting to monitor fuel trims at different throttle openings?

 

[DaveMcT]

My BMW bike with its two 600cc pistons was a 2008 so the ignition retard was probably quite aggressive. More modern ECU will constantly look for the best setting. Some of today's cars retard the ignition until the engine warms up. That heats the catalyst faster.

A mid 1990s Yamaha had a fixed timing map. Posh or normal petrol made zero difference. Some people modified the crank sensor to advance the spark timing but that meant you could only ever use posh petrol.

My 2001 Punto HGT (1750 twin cam) has a similar feeling to the 100HP Panda. It ran fine on 95 RON, but the performance felt crimped and it did show on the gas mileage - which was never good.

 

[TrevC]

My wife puts any fuel that's handy in her 1.2 500, but I almost exclusively use Shell V-power in my Hyundai i30 1.4 turbo. I did revert to standard E10 95 octane when fuel got eye-wateringly expensive last year, and noticed the mpg went down slightly. I also needed a new oxygen sensor during this period, but I'm sure that was coincidence, not the fuel.
I'm back on the V-power now, which is 99 octane E5. I've got the Shell loyalty app on my phone, which gives you a discount every 10 fillups and sometimes additional discounts in between. It also let's you pay at the pump at certain garages, which avoided having to mask up to pay during the pandemic restrictions, and is still handy now when people seem to be buying a week's food shop in the petrol queue!

 

[Muz R]

I found an Esso station selling 99 Ron today and filled up my Giulia @ £1.65 a litre!

I didn’t notice any difference at all but how would I on busy Sunday roads in the South East?

Fiat 500 will be filled up there next time it’s empty and I‘ll log any improvement in mileage or performance, should be easier than on the much quicker Giulia

 

[DaveMcT]

I reckon the slight improvement in mpg more or less pays for the additional cost. But my engine runs so much better on 99 it's well worth a few pence per litre.

 

[boatlon]

Pipip