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Model specific boards => Golf mk5 => Topic started by: Tongey on 16 March 2010, 14:30

Title: GTi Fuel
Post by: Tongey on 16 March 2010, 14:30
Sorry if this has been posted before. I've just bought a 55 plate GTi and i'm wondering do you have to stick with Super unleaded or can you stick in normal unleaded fuel.
Title: Re: GTi Fuel
Post by: flyingzard on 16 March 2010, 15:11
it'll take both fine unless it has been re-mapped. If it has then you need to use super
Title: Re: GTi Fuel
Post by: wuker on 16 March 2010, 16:13
I'd go for the 99RON and the performance is slightly better

MPG is a little improved as well
Title: Re: GTi Fuel
Post by: ub7rm on 16 March 2010, 17:37
GTI's are mapped for super from the factory so work best with it.  No harm apart from slightly worse power and fuel economy in using normal unleaded.  I think super has slightly better additives and detergents for keeping your engine clean in it as well but probably not that big a deal.
Title: Re: GTi Fuel
Post by: Tongey on 16 March 2010, 18:06
Thanx for the advice
Title: Re: GTi Fuel
Post by: Chris MKV on 16 March 2010, 19:38
The small increase in mpg also gives you a slightly improved tank range. This can be useful at times.
Title: Re: GTi Fuel
Post by: lowdown on 16 March 2010, 19:55
Shell V power now 99 octane and gives good results.  Stay away from supermarket petrol it's dreadful.
Title: Re: GTi Fuel
Post by: TagnuT on 16 March 2010, 21:01
Always used Shell V power or Tesco 99. Don't forget to get your V power points or club card points too.... :evil:

Some info on 95 Ron Vs 99 Ron.

http://www.thorneymotorsport.co.uk/tuning/Fuel_Test_Results.shtml
Title: Re: GTi Fuel
Post by: nick30 on 16 March 2010, 21:24
i always use VPower with or without a map. it may cost a couple of pence more but it will even out with the extra mileage and confidence your engine is getting what it deserves. my misses uses VPower Diesel and has reported better performance and mileage too  :smiley:

if you actually give a toss about your car i would say look after it dont feed it turkey twizzler fuel  :shocked:

on the fuel filler cap it states the fuel that needs to be in it i think its 98 or 99 but will check tomorrow  :nerd:

Title: Re: GTi Fuel
Post by: FamilyDub on 16 March 2010, 22:31
Fuel cap says 98 :nerd:
Title: Re: GTi Fuel
Post by: AlanD on 17 March 2010, 09:48
Always try and do whats best for the car so its Tesco 99 or V-Power for me.
Title: Re: GTi Fuel
Post by: Steve30 on 17 March 2010, 15:04
Always try and do whats best for the car so its Tesco 99 or V-Power for me.

Alan where are you getting the Tesco 99 ron , coz I cant find it any where? I know your in Croydon area? Thanks Steve

I use V-power diesel now anyway , but was wondering if there high grade diesel that Tesco do?
Title: Re: GTi Fuel
Post by: AlanD on 17 March 2010, 15:41
http://maps.google.co.uk/maps?q=elmers+end+tesco&ie=UTF8&hl=en&hq=elmers+end+tesco&hnear=Croydon,+UK&ll=51.398054,-0.048956&spn=0.004445,0.011362&t=h&z=17

The Tesco in Elmers End which down the road from me sell Tesco 99 and I find its always cheaper than V Power.
Title: Re: GTi Fuel
Post by: Steve30 on 17 March 2010, 17:14
http://maps.google.co.uk/maps?q=elmers+end+tesco&ie=UTF8&hl=en&hq=elmers+end+tesco&hnear=Croydon,+UK&ll=51.398054,-0.048956&spn=0.004445,0.011362&t=h&z=17

The Tesco in Elmers End which down the road from me sell Tesco 99 and I find its always cheaper than V Power.

Thanks Alan , any where else you know?  :cool:
Title: Re: GTi Fuel
Post by: Egbutt Wash on 17 March 2010, 18:18
Cheapest for me.  Especially in winter.
After extensive testing I have found that the higher octane fuel does make the power delivery more reliable.  The lower octane sometime causes the engine to back off on power for a few seconds, now and again.

Not worth the extra cash unless you are on the Isle of Man or at the Nurburgring.
Title: Re: GTi Fuel
Post by: simonkit on 17 March 2010, 20:16

  Why buy a car like the GTI & then not use the fuel that it's designed for?
 
  Definitely high octane !!

  Simon
Title: Re: GTi Fuel
Post by: Egbutt Wash on 18 March 2010, 13:46
It's designed for 95 octane.  I would not have bought one if it could not use normal petrol.

Try some 95.  The engine management takes a couple of miles to adjust after 98, then the car runs perfectly well.

At least I try these things.
Title: Re: GTi Fuel
Post by: AlanD on 18 March 2010, 14:21
It's designed for 95 octane.

Wrong, the engine in the MK5 was desgined to run on high octane fuel due the way the FSI engine works.

That doesnt mean 95 wont work as it clearly does.

The MK6 is a diffrent story and was designed to run on 95, this might be where your getting your wires crossed.
Title: Re: GTi Fuel
Post by: Egbutt Wash on 18 March 2010, 14:34
Perhaps some prankster has swapped my fuel flap sticker to one that says 95 RON super unleaded.
Title: Re: GTi Fuel
Post by: AlanD on 18 March 2010, 14:49
This was talked about ages ago and someone posted a link to details about how the FSI engine works. The higher octane allows the engine to run in FSI mode for a longer period of time.

Im not saying this is hard solid fact, but just passing info that was talked about last time.
Title: Re: GTi Fuel
Post by: FamilyDub on 18 March 2010, 15:09

^^^ Backing up Alan on this one. Talked to death elsewhere, though.

MKV: designed to run on 98+, will be ok on 95.
MKVI: designed to run on 95, better fuel will give decent gains, compared to MKV.

The FSI tech post would have been posted by ub7rm, maybe?
Title: Re: GTi Fuel
Post by: Egbutt Wash on 18 March 2010, 15:58
What I do notice is that Morrisons petrol gives worse mpg than ordinary Shell.
Title: Re: GTi Fuel
Post by: ub7rm on 18 March 2010, 16:15

^^^ Backing up Alan on this one. Talked to death elsewhere, though.

MKV: designed to run on 98+, will be ok on 95.
MKVI: designed to run on 95, better fuel will give decent gains, compared to MKV.

The FSI tech post would have been posted by ub7rm, maybe?

As you wish sir  :grin:

Regards FSI owners mainly.

The higher the octane rating of the fuel the longer the FSI engine will run in FSI mode.

You see, when the FSI is running in 'Fuel Stratified Injection' mode it creates a lot of NoX (NoX - Very bad as far as emisions go) due to it being such a lean burn, so it has a NoX Cat which abrorbs the NoX, once its full the Nox probe (fancy lambda probe) senses this and the engine switches back to normal running and can safely clear the NoX out with the other gases through the main Cat so it can switch back into in FSI mode again.

The problem with octane levels is, and this is just an example depending on driving styles.

Out of 100 miles average :-

95RON - 90 miles normal, 10 miles FSI (lots of NoX made in FSI mode)

97+RON - 60 miles normal, 40 miles FSI (some NoX made in FSI mode)

Now regardless of what anyone says this is how the engine is built and as its more efficient in FSI mode VW always recommend the highest octane rating for this reason, they did introduce a 1.4FSI for the uk market that is made to run on 95RON fuel for longer but you want to see the size of the NoX Cat, more like a tanker. lol

And after all that, you will get better miles to the gallon running 97+RON regardless of it being an FSI, its they way they are made these days, the ecu recognises when the fuel mixture combusts and will adjust it accordingly, the cheaper the fuel the more retarded the timing, the more retarded the timing the less power, the less power the more you 'need' to put the foot down.


Its part of the GTI hints and tricks thread in the maintenance section ...
Title: Re: GTi Fuel
Post by: ub7rm on 18 March 2010, 16:16
What I do notice is that Morrisons petrol gives worse mpg than ordinary Shell.

I believe Morrisons fuel contains more biofuel than most other petrol ...
Title: Re: GTi Fuel
Post by: Egbutt Wash on 18 March 2010, 16:33
What I do find is when I have a full tank of 99 my mpg drops.  Because I drive hell for leather to get my monies worth out of the dear stuff.  I even use the flapsters.
Title: Re: GTi Fuel
Post by: FamilyDub on 18 March 2010, 16:58
The FSI tech post would have been posted by ub7rm, maybe?

As you wish sir  :grin:

 :grin:

What I do find is when I have a full tank of 99 my mpg drops. 

^^^ I notice a performance differential, but no gain/loss in mpg from either.

Although to be fair, my mileage/use is random and erratic, so I wouldn't like to be a test bed...

...unless someone is willing to pay for ten tanks of 99 and ten tanks of 95 to compare...  :evil:  :grin:
Title: Re: GTi Fuel
Post by: AlanD on 18 March 2010, 17:37
Whats you account name, sort code, account number etc and I'll send the monies over . . . .:D
Title: Re: GTi Fuel
Post by: marty341 on 18 March 2010, 20:58
Markv gtis are superb cars! look after it, and it will look after you :wink:

We all know which it prefers!? V-Power/Tesco Super all day long.
Title: Re: GTi Fuel
Post by: scotland67 on 19 March 2010, 09:10
According to the VW GTI Brochure, page 24, technical notes, 04, "Thanks to the knock control,unleaded four star(at least 95 ron) can be used instead of unleaded super plus"
Title: Re: GTi Fuel
Post by: FamilyDub on 19 March 2010, 09:53
According to the VW GTI Brochure, page 24, technical notes, 04, "Thanks to the knock control,unleaded four star(at least 95 ron) can be used instead of unleaded super plus"

^^^ which brochure?
Title: Re: GTi Fuel
Post by: scotland67 on 19 March 2010, 10:55
The free Brochures you can get from any dealers showroom. I quoted from the 2009 brochure but exactly the same info is in my 2006 brochure, which I still have.
Title: Re: GTi Fuel
Post by: AlanD on 19 March 2010, 11:08
It does indeed say it. To quote it exactly it says - "Thanks to the knock control, unleaded fourstar(at least 95 RON) can be used instead of unleaded Superplus. In order to achieve maximum fuel consumption benefits on the FSI engine,Ultra Low SulphurPetrol (ULSP) must be used."

http://www.scribd.com/doc/16287603/golf-2007

Page 21

 :undecided: :undecided: :undecided: :undecided:
Title: Re: GTi Fuel
Post by: FamilyDub on 19 March 2010, 11:16

That's quite contradictory.  :undecided:
Title: Re: GTi Fuel
Post by: AlanD on 19 March 2010, 11:18
VW are contradicting themselves by saying that in the brochure then sticking a big 98 sticker on the filler gap.
Title: Re: GTi Fuel
Post by: Steve30 on 19 March 2010, 12:03
VW are contradicting themselves by saying that in the brochure then sticking a big 98 sticker on the filler gap.

+1 agree!! :cool:
Title: Re: GTi Fuel
Post by: Egbutt Wash on 19 March 2010, 13:13
VW are contradicting themselves by saying that in the brochure then sticking a big 98 sticker on the filler gap.

+1 agree!! :cool:

My '08 has a big 95 sticker on the flap.  Perhaps the car was improved over the years (I'm assuming those with 98 stickers are old cars)
Title: Re: GTi Fuel
Post by: Steve30 on 19 March 2010, 13:15
VW are contradicting themselves by saying that in the brochure then sticking a big 98 sticker on the filler gap.

+1 agree!! :cool:

My '08 has a big 95 sticker on the flap.  Perhaps the car was improved over the years (I'm assuming those with 98 stickers are old cars)

Looks like somone has put the wrong sticker on it Egbert?? :wink:
Title: Re: GTi Fuel
Post by: bobotheclown on 19 March 2010, 15:41
my 08 car has a 95 sticker on it too.

have always fed her v-power though.
Title: Re: GTi Fuel
Post by: ub7rm on 19 March 2010, 17:20
my 08 car has a 95 sticker on it too.

have always fed her v-power though.

Its the wrong sticker, someone (TT) did a check on the part number of the sticker and found that it referred to a different car!

As said, 1000000 times, it is perfectly OK and safe and not a problem in the slightest to use 95.  No problems.

BUT

The car has been optimised to run on 98.  Using 98 gives the best (and in fact the official stated) performace and fuel economy figures.  There are many places where 98 is not available so of course VW are going to give people the option - they would have a very limited market if they didn't!

Title: Re: GTi Fuel
Post by: ifti on 19 March 2010, 17:24
My car is an '08' and I have the 98ron sticker.
Title: Re: GTi Fuel
Post by: AlanD on 19 March 2010, 18:42
my 08 car has a 95 sticker on it too.

have always fed her v-power though.

Its the wrong sticker, someone (TT) did a check on the part number of the sticker and found that it referred to a different car!

As said, 1000000 times, it is perfectly OK and safe and not a problem in the slightest to use 95.  No problems.

BUT

The car has been optimised to run on 98.  Using 98 gives the best (and in fact the official stated) performace and fuel economy figures.  There are many places where 98 is not available so of course VW are going to give people the option - they would have a very limited market if they didn't!



Right thats 100% confirmed it then. In future we will refer back to this thread.