T27 1.8 Valvematic and super unleaded

[Cessna]

I've decided to try super unleaded for a while, to see if I can notice any improvement in performance or fuel economy. Does anyone know if the car will make use of the extra performance available? I remember when 95 octane fuel became common that some old cars required the ignition to be retarded a little so they ran properly on it, and that some more modern cars can automatically adjust the timing and other engine operations to make best use of whatever octane fuel is used. So I was wondering if the T27 with a 1.8 Valvematic can do so, or if I am completely wasting my time and money (with super unleaded seemingly ~10p more expensive per litre). I've just filled up with super unleaded and a couple of long journeys to make soon, so I will report back what (if anything) I notice that is different.

[yossarian247]

I occasionally ran my 2009 Auris 1.6 Valvematic on super unleaded. It did appear to run a little smoother and give better fuel economy on it. The gain in economy wasn't enough to cover the increased cost of super though so I usually used standard unleaded.

[Konrad C]

I would like to try 97/98/99 octane fuel with my 1.8 Valvematic ('58 plate 2009 Tourer). The owners manual does state that gasoline (petrol to me) of octane of 95 or higher, plus ethanol is up to 10% content can be used. This means that the ECU covers all the variables of the fuel being used, so long as the fuel used is within the parameters stated above!
I have not noticed any difference in consumption or performance, but then my car usage has been less in recent times. I have done a few motorway trips, and everything felt the same as before.    

[Shavestick]

On 11/15/2021 at 7:41 AM, Konrad C said:

I would like to try 97/98/99 octane fuel with my 1.8 Valvematic ('58 plate 2009 Tourer). The owners manual does state that gasoline (petrol to me) of octane of 95 or higher, plus ethanol is up to 10% content can be used. This means that the ECU covers all the variables of the fuel being used, so long as the fuel used is within the parameters stated above!
I have not noticed any difference in consumption or performance, but then my car usage has been less in recent times. I have done a few motorway trips, and everything felt the same as before.    

we do few long trips in our 2010 Tourer 1.8 TR every month.

 

I tried E10 vs E5 and the Esso stuff (no ethanol added).

There is a brim to brim difference of about 9% between the 97ron E5 and bog standard Tesco E10 and pushing to 10% better consumption with Esso super.

[rickywales]

I have been running mine on 95E10 all year without problem I only have the choice of 95E10 or 98E5 here in Finland 

[TonyHSD]

E10 it’s not a problem but it’s a lower grade less energy density fuel than E5 or E0 and so gives less power and less lube properties, it does burn cleaner though but when your engine uses more there is absolutely no benefit of it. Ethanol is also used as octane booster therefore my theory is that the E10 95 petrol is lower quality base fuel than previously E5 95. Auris hybrid on E5 99 drives noticeably better than if with E10 95, most Tescos has 99 E5 for the same price as E10 95 from bp, esso or Shell. Definitely worth it 👍

[Cyker]

I do wonder how the mix has changed - In theory they could have just removed some of the octane boosters that normally goes in petrol and replace it with the E10, which would leave more volume for actual fuel, or e.g. other additives for, say, cleaning.

That's one thing a lot of these articles deploring E10 miss - If you add 5% more ethanol to E5, 5% of something else has to be removed and that will either be petrol, or additives, or some mix of the two. I think that's why the mpg impact hasn't been as noticeable as people were predicting, as maybe only 1% of petrol has been lost, but also 4% of additives which are now redundant, as ethanol is an octane booster and a cleaning agent! But maybe the octane boosters have been replaced with 2% fuel stabilizer/emulsifier to stop water from being absorbed and clumping up so fast...?

If anyone works in the fuel industry and has some insight, I'd love to know!!

 

 

[Cessna]

Apologies for the thread resurrection, but I did say I would report back after using super unleaded for a while. Basically I couldn't really tell any difference in performance or fuel economy, so I have switched back to E10, given the 10-15p difference in price per litre.