What Octane of Fuel to Use in TSI Engines? Seat Ibiza MK 5 FR 1.2TSi

turnipfarmer

Active Member
Aug 22, 2010
79
0
I am wondering what peoples point of view is on this? I know in the manual and in the filler cap it says to use 95 Octane for my 1.2TSI but I read on other forums eg Skoda, Audi, VW and people on there say to use 98+.

Also I believe those who have the 1.4TSI it says to 98+? I wonder why it is different for the 1.2 compared to the 1.4.

I feel I get more MPG using Tesco Momentum 99 than I did with its bog standard Tesco Unleaded and also heard that it does not do an engine any good using the wrong type of Octane fuel. Really for us in the UK we only have the option of two fuels I believe, Tesco Momentum and Shell V-Power.

Just wondering what other Seat Ibiza owners think?
 

Nutkin

Pop-a-Keg ya?
Aug 24, 2006
2,581
0
Schnaitsee
it doesn't say use 95, It says MINIMUM 95, any car with the ability to adjust timing should benefit slightly from higher octane.

Whether you believe in the cleaning agents etc that is up to you.

I personally from experience in automotive engineering believe that the premium fuel is better, how much i do not know but if it only costs me a pintsworth per tank of fuel Ill happily give it up to know i am running on the best there is freely available.
 

mobil one

Active Member
Jul 15, 2011
228
2
north east
in my 1.2 fr, which has the same 1.2tsi engine,i use millers ecomax additive, at a cost of £12 to treat 500 litres of fuel.
much cheaper than the premium fuels, like bp ultimate, shell v power etc.and has the same ingrediants to keep valves clean, boosts octane rating up by 2 points, etc.
have used this for a few years now in my previos cars which were volvos whithout any troubles.
 

RUM4MO

Active Member
Jun 4, 2008
6,407
491
South Scotland
I've not got a TSI engine, but, I believe these engines are direct injection, so the merits of using additives designed to clean the inlet tract are probably minimised. I tend to go along with Nutkin and stick with a quality fuel which is slightly higher octane rating and is really loaded up with effective cleaners. BTW, VAG do have kit to chemically decoke these direct injection engines as well as doing the same job on indirect injection engines - which I reckon will be what a growing number of other independant garages are now offering.
 
Last edited:

Nath.

The Gentlemans Express
Jan 1, 2006
8,622
16
EASTLEIGH, HAMPSHIRE
It says min 95 so as long as what you put in is min 95 you will be fine and the engine will run perfectly well.

If you want to put higher octane in then that's up to you. If you can tell the difference you're a hero.
 

RUM4MO

Active Member
Jun 4, 2008
6,407
491
South Scotland
It says min 95 so as long as what you put in is min 95 you will be fine and the engine will run perfectly well.

If you want to put higher octane in then that's up to you. If you can tell the difference you're a hero.
I think that you will find what is happening more and more with modern engines is, they can be run with low quality lowish octane fuel, but the engine could suffer due to the build up of deposits in the combustion areas. How much they will suffer will depend on the ambient temperature and "type" of usage, short jouneys in town - long journeys on open road. Now the difference between main UK brands of proper petrol is - 94/95 = meets minimum engine "burn" requirements but has very little additives to keep the engine clean, 97/98 = exceeds minimum engine "burn" requirements and is loaded with additives.

So, if that makes any sense to you, and you want to keep the engine in good condition as long as you own the car, then maybe "see" the logic in using higher grade fuel - there is sometimes the added bonus of cheaper motoring costs as a cleaner more efficient engine using higher octane fuel, should return higher MPG. The other issue is that "it is said" that modern VAG engines - ie from roughly 15 years back to present, are known to be more prone than some other brands to being "dirty" engines, and this means bunging up their combustions areas and cats - so that includes getting sticking piston rings quickly with associated oil usage I'd reckon.

Personally, I'd say that we, the end users are getting stuffed by some engine manufacturers and if it says 95 octane is okay, then that should mean its okay for all conditions that that engine will see in service! They are just not being very truthful!!
 
Last edited:

Nutkin

Pop-a-Keg ya?
Aug 24, 2006
2,581
0
Schnaitsee
It says min 95 so as long as what you put in is min 95 you will be fine and the engine will run perfectly well.

If you want to put higher octane in then that's up to you. If you can tell the difference you're a hero.

You can tell in the 1.4tsi, when the petrol crisis on i had to use 2 tanks of 95 and when i floored it to get onto a motorway i thought something was wrong with the car!
 

Ben-ibizaFR

Active Member
Sep 23, 2012
455
0
Preston
Lover super unleaded ! swear by Tesco 99 and vpower ! Much more mpg. Try it for yourself. Best way. Put x liters in the tank. Record your mpg. Then do same again with super unleaded :) bit of a rough test of course. However should do the trick !
 

phil750

Active Member
Jul 24, 2012
213
1
in my 1.2tsi i tend to fill it up with 97 (from any petrol station) and then add the fuel additive stuff as well which probably puts it up to 98.

From experience i would say the additive only really makes a big difference when doing long motorway journeys. I did a 230 mile round trip to leeds and got very good mpg (49).

To me it not actually that much expensive to use 97 and fuel additive and will pay off in the long run. (ive had previous cars when just use 95 and had a few fuel injection problems)
 

GraemeB

Active Member
Sep 3, 2012
70
0
Monifieth, Angus
I have tried Esso 95 and Esso premium, Tesco 95 and Tesco 99 and as far as I can tell there's nothing in it as far as oomph or fuel consumption is concerned. I've got a 1.2 tsi with about 2500 miles on the clock and the comparison has been same journey to and from work in the same traffic conditions.
 

GraemeB

Active Member
Sep 3, 2012
70
0
Monifieth, Angus
According to the handbook it ideally wants 95 RON but it can tollerate 91 RON at reduced power. Giving it 99 RON premium fuel won't do it any harm at all, it might tickle your ego and drain your wallet a tiny bit faster but it won't make any more power. A quality 95 RON fuel will contain the detergentents to benefit your engine. At the end of the day your tank will take around 40 litres so the 5p a litre difference will be £2 a tank.
 
Last edited:

Ben-ibizaFR

Active Member
Sep 23, 2012
455
0
Preston
While on topic of fuel, when my car alerts me to the dreaded 40miles to empty, with the fuel light, once I have reached zero, do I still have around 30miles to go before true empty ?
 

GraemeB

Active Member
Sep 3, 2012
70
0
Monifieth, Angus
When that happens there's still at least 4 litres in the tank. How far it'll go depends on what you do with your right foot.
 
Last edited:

Ben-ibizaFR

Active Member
Sep 23, 2012
455
0
Preston
Ahh okay at :) I'm going to allow a 30miles I think, bit annoying because it make you think you miles from a tank is awful !
 

phil750

Active Member
Jul 24, 2012
213
1
What fuel adatives are you using ? Find redex is pretty gd !
I use it the millers stuff from halfords, costs £12 and treats 500L .
I dont do much millage so its so cheap and lasts me like 6 months so
even if it doesnt do anything at all im only losing a tiny bit of money
 

JAM11E

Active Member
Nov 16, 2012
47
0
Just use petrol, dont see why everyone asks this question.

You would only see a gain if you had some 500bhp machine

Sent from my GT-I9300 using Tapatalk 2
 
Listers, parts supplier