E10 v E5 Petrol

[DRM]

I’ve filled up with E5 this time, hoping that it will flush through/clean the fuel system of any deposits from the E10 petrol, what I have noticed is that the car is quieter on tick over, pulls away stronger, and more smoothly, and according to the dashboard MPG information, seems to be doing about 8 to 10% better on fuel consumption, which I’m not saying is wholly accurate but as an indication is showing another improvement, I also know from speaking to a mechanic at a Motorbike dealers, that E10 petrol leaves horrendous rock hard deposits in the fuel systems of bikes that go into storage over winter, which they have a dreadful time repairing, has any one else noticed the same? The petrol was purchased from the same place as the previous E10 too.

 

[HMS_Dave]

I never really noticed any difference. Ethanol essentially has 2 negatives for the car. It has solvent properties so bad for seals and gaskets, especially in older cars and it is hygroscopic so water can get into places it shouldn't and can potentially corrode metals inside the engine which could explain "hard deposits" after storage. In modern vehicles it's not a really a problem. But if mechanics are reporting otherwise then im certainly in no position to challenge them. I'd probably run a tank on "super" before and after storing and maybe some fuel system cleaner.

 

[johnnyb47]

I always use Redex each time I fill up with E10
I suppose it's like using E5 all time.
I £5 bottle lasts for two complete

 

[Drago]

Never noticed a diffenrces, but the new non turbo petrol cars ive owned have all been designed to run on E10 anyway.

 

[Gillstay]

It does affect very small engines if it separates out but not to a huge difference.

 

[gbb]

Son In law is a garage mechanic and always recommends you use E5. His logic ? and its personal preference and simple logic, nothing scientific...we havnt seen the longer term consequences of using E10 on cars particularly cars that were being built PRIOR to the introduction of E10.

E5 tends to be about 10p litre dearer than E10. My simple arithmetic tells me it makes less than a litre or so difference each fill up, so why not invest a little in better fuel for very little loss.

It's better for the fuel system in general.

It's (probably) better for fuel consumption.

I err toward E5 but occasionally do use E10 but comparing consumption figures is slightly difficult because (I believe) engine management systems take a little while to adapt to the different fuels. I've seemingly had the same consumption using E10, then sometimes seen improvement using E5. It's too variable to be sure IMO.

Ultimately, I err toward E5.

 

[sevenfourate]

Is Esso Synergy Supreme still 0% Ethanol - does anyone know ?

 

[Jameshow]

I use supermarket fuel cheapest possible...
May contain petrol!!
Or diesel in my case!!

 

[fossyant]

My 22 year old car is run on Super as I don't use it much. Last time it got a tank was back in May for a camping trip - I've not put in any fuel since. E10 absorbs more moisture so the fuel 'goes off' quicker. I get a good 10% better fuel economy on Super, more than outweighs the cost. Can't tell the difference on the Qashqai or Aygo.

 

[Accy cyclist]

I put E5 in my 12 year old Fiat 500 if i can, but the odd time I've had to put E10 in, as the petrol station didn't sell, or have any E5. I don't suppose 10 days of running on E10 will have any detrimental affect as I'll add a quarter of a bottle of Redex if I have to buy E10, and I always wonder which type of fuel the 2 previous owners used. Though going off the car's log book history, with all the services etc it had before I bought it, I'd like to think they used E5.

 

[HMS_Dave]

I put E5 in my 12 year old Fiat 500 if i can, but the odd time I've had to put E10 in, as the petrol station didn't sell, or have any E5. I don't suppose 10 days of running on E10 will have any detrimental affect as I'll add a quarter of a bottle of Redex if I have to buy E10, and I always wonder which type of fuel the 2 previous owners used. Though going off the car's log book history, with all the services etc it had before I bought it, I'd like to think they used E5.

I wouldn't worry about it. Most cars from 20 years ago were compatible, your tweed machine will be fine. I personally would be a tiny bit more concerned if it was parked up for months but then it would make sense to prepare the car for that, whatever fuel is in it.

 

[Profpointy]

my oldish Saab 2.3l turbo petrol, and my sadly gone motorbike, 1000cc 130HP were both specified to run on E10. Neither was exactly low performance. I trust the manufacturers to know what it supposed to run on and they ran fine, even if I rarely used E5 - only when I first got the bike and didn't know

 

[CXRAndy]

I always use 99 do ron ron

 

[rogerzilla]

E5 doesn't cost more to make than E10 - probably less - but the government makes the fuel suppliers sell it only in the higher octane "super unleaded" pumps to discourage its use. Most cars won't benefit from the higher octane rating.

Apparently Esso E5 doesn't even contain the 5% ethanol, although this was in one test and things will change from time to time. You could even be lucky and get E10 with < 10% ethanol, as the 5 and 10 are maximum percentages only.

My old CX-5 ran like a dog on E10, needing one gear lower on hills. It had a very high compression engine and I assume the knock sensor retuned it for less power. The Mazda 3 with SkyActiv-X engine doesn't seem bothered. It pinks more audibly but it's designed to.

I would definitely avoid E10 if you're taking more than two months to get through a tankful.

 

[Psamathe]

Ethanol essentially has 2 negatives for the car. It has solvent properties so bad for seals and gaskets, especially in older cars and it is hygroscopic so water can get into places it shouldn't and can potentially corrode metals inside the engine which could explain "hard deposits" after storage.

I have a bottle of fuel "conditioner" I got from a motorist store. An additive for fuel that says it converts E? back to standard unleaded (add different amounts for the different Es). I got/use it for garden lawnmower which apparently isn't E fuel rated and maybe involves more "storage" as used less often than most cars.

I've no idea how effective at protecting the engine nor performance as mower is well past any life expectancy.

Ian