put wrong fuel in car - help

iammumtoone

I just put super unleaded in rather than unleaded


Does this matter? Car was empty before I filled and by the time I realised I had put in 3/4 tank. Should I top it up to full with normal unleaded? Or does it make no difference (apart from the cost) my car is a 6 year old basic 1.2 engine.


EDIT: just looked a the fuel cap it says to use super 95 octane.


Thanks

MovingForwards

Makes no odds super or unleaded. Just costs more!

You only need to worry if you put diesel in a petrol tank or petrol in a diesel.

Manxman_in_exile

We once had problems with a lamda(?) sensor.


We were advised that occasionally using super-unleaded might be useful in preventing this happening again.


Whether that's bo77ocks or not I don't know, but still do it every half dozen or so fill ups.


(Is it bo77ocks? Am I wasting a few quid a year?)

Arklight

Manxman_in_exile wrote: »

We once had problems with a lamda(?) sensor.


We were advised that occasionally using super-unleaded might be useful in preventing this happening again.


Whether that's bo77ocks or not I don't know, but still do it every half dozen or so fill ups.


(Is it bo77ocks? Am I wasting a few quid a year?)

Afaik super unleaded is just the same fuel with a higher octane content. Octane is a non combustible chemical that spaces out the petrol molecules. it allows for a form of pre-ignition in performance engines that inject fuel at high pressures.

It shouldn't make any difference to a normal engine, other than that there is a tiny bit less combustible petrol in a litre of high octane fuel, compared to the 95 equivalent.

Scrapit

Petrol in a petrol car. What's the problem here?

molerat

The only thing damaged is your pocket.

wgl2014

Arklight wrote: »

Afaik super unleaded is just the same fuel with a higher octane content. Octane is a non combustible chemical that spaces out the petrol molecules. it allows for a form of pre-ignition in performance engines that inject fuel at high pressures.

It shouldn't make any difference to a normal engine, other than that there is a tiny bit less combustible petrol in a litre of high octane fuel, compared to the 95 equivalent.

However retailers tend to add some extra detergents to their 'premium' fuels that are supposed to remove carbon build up etc (cue snake oil discussion).

JamoLew

There are slight differences to additives and detergents between standard and super fuels.
For petrol there is clear evidence that certain cars/engines perform better and more efficiently with the super variant - I used to own a 300bhp+ Subaru and can attest to this.
Different cars run optimally with different fuel - this may be an urban myth but a colleague mentioned to be once the a Nissan GT runs best on Tesco super unleaded

Apodemus

Arklight wrote: »

... Octane is a non combustible chemical that spaces out the petrol molecules. it allows for a form of pre-ignition in performance engines that inject fuel at high pressures.

It shouldn't make any difference to a normal engine, other than that there is a tiny bit less combustible petrol in a litre of high octane fuel, compared to the 95 equivalent.

Eh? No, octane is definitely combustible. The quoted octane rating is simply a means of comparing how the fuel responds under compression. Since a petrol engine works by igniting fuel with a spark, you don’t want the fuel to ignite under compression alone (as would happen in a Diesel engine). A higher octane rating means that you can have a higher compression without the fuel igniting prematurely. If your engine doesn’t need to work at higher compression, then you don’t get any benefit from the higher octane rating, but suffer no harm. As mentioned above, there may be other additives in the more expensive product that may or may not be worth paying for.

Kentish_Dave

Octane spaced out the molecules?

Someone here certainly is keen to make themselves look very stupid today. If you don’t have the first clue about something, why wade in?

Sometimes it’s better to say nothing, and risk people thinking you stupid than to say something and confirm it...

oldagetraveller

Nothing to worry about. According to some, though, your car will be much faster, much quieter, you'll achieve more m.p.g., cleaner exhaust etc..:rotfl: