# Unleaded vs Super Unleaded



## TheDude (Apr 4, 2009)

I have read that it is recommended that Super Unleaded petrol is used for the TT.

However I dont know anything about petrol so would love some advice as to what everyone else uses?

If its a case of paying more just for a slight performance boost then I cant say it will interest me but if it is better for the car/engine that I use it then I will obviously do so.

How much does it cost compared to petrol and is it widely available?

Should hopefully have car in a couple of weeks so really need to know I guess. :mrgreen:


----------



## Gemini (Apr 26, 2009)

The difference between normal unleaded and super unleaded is in the RON rating (Research Octane Number). Nornal unleaded is usually around 95 RON, Super Unleaed varies depending where you buy it from but is usually 97 - 99 RON. The higher a fuels octane level the better its resistance to knocking (i.e the fuel-air mix in the cylinder exploding instead of burning in a controlled way). This tends to be more of an issue for performance engines.

A car that has an ECU that recognises when Super Unleaded is being used can benefit from smoother engine running, better performance and sometimes better mpg. The TT ECU and many performance engines will recognise when they are burning Super. If I was you I would try both (but no point in mixing them) and see which your car prefers. Super is generally a couple of pence more expensive per litre which equates to a couple of pounds on a tank full - not much really.


----------



## TheDude (Apr 4, 2009)

Gemini said:


> The difference between normal unleaded and super unleaded is in the RON rating (Research Octane Number). Nornal unleaded is usually around 95 RON, Super Unleaed varies depending where you buy it from but is usually 97 - 99 RON. The higher a fuels octane level the better its resistance to knocking (i.e the fuel-air mix in the cylinder exploding instead of burning in a controlled way). This tends to be more of an issue for performance engines.
> 
> A car that has an ECU that recognises when Super Unleaded is being used can benefit from smoother engine running, better performance and sometimes better mpg. The TT ECU and many performance engines will recognise when they are burning Super. If I was you I would try both (but no point in mixing them) and see which your car prefers. Super is generally a couple of pence more expensive per litre which equates to a couple of pounds on a tank full - not much really.


Thanks, will try a tank of each.

Do you guys normall fill your tank or is it better to just put half a tank in?

Just thinking about weight, I know it wont make a difference but would be nice to know.

I believe the petrol tank is 55 litres.

Still cant beleive Im going to be driving this soon, its going to blow my Corsa out of the water!


----------



## Tim G (Feb 16, 2005)

My TT is mapped to run on Super. In fact, running it on the normal stuff brings on the engine management light it hates it so much! I use Tesco 99, its 5p more p/litre, so not really a bg deal.

My Mini Cooper S (last car) also seemed to run loads better on super than normal.

I would be interested to know if '97' or '99' actually improves MPG to the extent that it becomes worth the extra 5p p/litre. A lot of people say it can/ does but I'm not really sure!


----------



## zorpas (Jul 30, 2008)

I always use super unleaded and not only for performance reasons but basically for improved fuel economy and also because its best for the engine. The price difference is usually some cents, so no worries there.

I even use super unleaded for my bike which is a 2 cylinder engine and no performance beast..


----------



## Wallsendmag (Feb 12, 2004)

Once again the search function works wonders.


----------



## phil3012 (Jul 25, 2008)

TheDude said:


> Gemini said:
> 
> 
> > The difference between normal unleaded and super unleaded is in the RON rating (Research Octane Number). Nornal unleaded is usually around 95 RON, Super Unleaed varies depending where you buy it from but is usually 97 - 99 RON. The higher a fuels octane level the better its resistance to knocking (i.e the fuel-air mix in the cylinder exploding instead of burning in a controlled way). This tends to be more of an issue for performance engines.
> ...


I don't think trying a tank of each will work as apparently it takes a few tanks for the ECU to adjust.

I had this discussion many times on the SEAT forum. The Leon FR used the same engine as the TT and the Cupra a similar one, there was mixed oppinions but I ran the Cupra on Super Unleaded as that's what SEAT recommended. It had to be V-Power or Tesco 99 RON though as other makes are only 97 RON, when 98 RON or above is recommended.

When I was ordering my TT I did ask the dealer about which fuel a petrol TT should use, his opinion was a newer Mk.2 TTs run on either with no difference but older Mk.2s 98 RON was recommended .


----------



## ben.redtt (Dec 18, 2006)

witch TT would benefit the most from using super unleaded v6 vs turbo?


----------



## misterpro (Sep 1, 2008)

I might be wrong here but I assume turbo, as it's burning fuel under higher pressure (from the turbo, and especially on S or RS models) so it starts knocking easier.


----------



## hanzo (Apr 6, 2009)

WHATEVER YOU DO !!! DONT USE THE NORMAL!!!!!
:!: :!: :!: :!: :!: :!: :!: :!: [smiley=argue.gif]


----------



## MP (Feb 22, 2008)

I have a fuel card from work, so always know how many miles I get from each tank full, over the past year and 17000:

Unleaded = 38 mpg
Super Plus = 34 mpg

And thats, for example 6 tanks in a row of tesco super plus, not just the odd tank of each here and there.

But I still fill up with tesco super plus only 5p a litre more and the car just seems more powerful, pulls better from lower revs.

So my conclusion = Normal gets you better MPG (I think it's because I don't boot it so much) but super plus gets a bigger smile on your face!


----------



## MP (Feb 22, 2008)

Checked the DIS after a run down to the Wirral on friday and it said my average over the 60 mile journey was 44.5 MPG.


----------



## Toshiba (Jul 8, 2004)

Normal 95


----------



## TheDude (Apr 4, 2009)

wallsendmag said:


> Once again the search function works wonders.


Dont really see this as a constructive post the thread got lots of responses and served a purpose??? :roll:

Thanks for the help to all those who replied and voted, I will have a look about to see what my local petrol stations offer.


----------



## Fissues (Aug 11, 2008)

For all it's worth, on my US spec. TTS, the manual states you MUST use super.


----------



## UKLooney (Oct 15, 2003)

09TTSQR said:


> For all it's worth, on my US spec. TTS, the manual states you MUST use super.


In the UK, regular unleaded petrol is 91 RON. Premium unleaded petrol is 95 RON which is what you call super in the US. 95 RON is the minimum grade for the TT in the UK too.


----------



## Toshiba (Jul 8, 2004)

No its not. Reg is 95 in the uk, super is 97,98 and 99 for v power.
95 is min for the TT


----------



## garvin (May 7, 2002)

Depends:-

Turbo engine - use super unleaded (97 - 99 RON), makes quite a difference in the performance stakes.

Normally aspirated engine - use 95 RON, no real discernible performance advantage unless ragging the wotsits off it.

Fuel consumption - theroretically, for the same driving, the higher octane fuel should give the advantage - same calorific value but more advanced ignition should give more power for same fuelling - however, the differences are probably very marginal and highly unlikey to return the 5% to 10% improved mpg required to recoup the price premium.


----------



## drjam (Apr 7, 2006)

Toshiba said:


> No its not. Reg is 95 in the uk, super is 97,98 and 99 for v power.
> 95 is min for the TT


Actually if you look at most UK pumps, UK Looney was right: even though it's the "standard" petrol, 95 is described as "Premium Unleaded".
Haven't seen 91 for yonks.


----------



## zorpas (Jul 30, 2008)

So, is using the 95 'bad' for the TT after all ?
or its jsut better using 98 ?


----------



## drjam (Apr 7, 2006)

zorpas said:


> So, is using the 95 'bad' for the TT after all ?
> or its jsut better using 98 ?


Does it not tell you in the user manual? 
(can't speak for MKII, but certainly it states in my MKI user manual that 95 is fine)


----------



## zorpas (Jul 30, 2008)

drjam said:


> zorpas said:
> 
> 
> > So, is using the 95 'bad' for the TT after all ?
> ...


yes, but im not asking what the manual says obviously 
im asking the owners opinion


----------



## UKLooney (Oct 15, 2003)

Toshiba said:


> No its not. Reg is 95 in the uk, super is 97,98 and 99 for v power.
> 95 is min for the TT


No, popular misconception. In the UK 'Regular' is 91, 'Premium' is 95, 'Super' is 97,98,99 etc.
You don't see much 91 around anymore.

see here http://en.wikipedia.org/wiki/Gasoline#Energy_content


----------



## squiggel (May 16, 2006)

zorpas said:


> So, is using the 95 'bad' for the TT after all ?


No.

8)


----------



## drjam (Apr 7, 2006)

zorpas said:


> drjam said:
> 
> 
> > zorpas said:
> ...


Fair enough. 
My point was more that user opinion might help with your second question, but the manual will answer the first one.


----------



## Gone (May 5, 2009)

I picked up my first TT a couple of weeks ago and took it to Wak last night for a checkover and a few specific checks. The manual recommends using 98 RON although the car will run fine on 95 as a minimum. I assumed this was precautionary backside-covering nonsense from the maunufacturer, and decided to run on 95 RON.

Wak had a good look over the car and we did a couple of data logging runs - this showed peak air flow reading of only 150-160 g/s from the MAF which should be up at 180+, and corresponded to peak BHP of 180-190, not the 225 I'd expect. A new MAF didn't make any difference, and the car is fine w.r.t. boost leaks.

Basically Wak's opinion was that the increased tendency for knocking on 95 RON makes the engine adjust the ignition timing to reduce boost and prevent damage, thereby limiting power output. I plan to run the tank and down and use V power for a few tankfuls before logging again.

HTH


----------



## Tim G (Feb 16, 2005)

badyaker said:


> I picked up my first TT a couple of weeks ago and took it to Wak last night for a checkover and a few specific checks. The manual recommends using 98 RON although the car will run fine on 95 as a minimum. I assumed this was precautionary backside-covering nonsense from the maunufacturer, and decided to run on 95 RON.
> 
> Wak had a good look over the car and we did a couple of data logging runs - this showed peak air flow reading of only 150-160 g/s from the MAF which should be up at 180+, and corresponded to peak BHP of 180-190, not the 225 I'd expect. A new MAF didn't make any difference, and the car is fine w.r.t. boost leaks.
> 
> ...


Dont forget to report back after you've done this. Will be interesting to see the results.


----------



## SAJ77 (Nov 16, 2008)

After reading this thread yesterday, i filled up with V power after only using standard unleaded.

Car was fine but on my journey home from work just now it was rough and appearing to missfire :?

Done about 50 miles from an empty ish tank on V Power.

Oh well, its getting remapped this month, sure they'll sort it!!


----------



## Gemini (Apr 26, 2009)

SAJSTER said:


> After reading this thread yesterday, i filled up with V power after only using standard unleaded.
> 
> Car was fine but on my journey home from work just now it was rough and appearing to missfire :?
> 
> ...


Phil3012 said in his post "it takes a few tanks for the ECU to adjust". If he is correct then your ECU may not have adjusted yet if you have only done 50 miles. Things may settle down once you have clocked up a few more miles on the new fuel.


----------



## Gone (May 5, 2009)

Tim - will do, might even be able to put a few graphs up if I can make this computer lark work

Forgot to say earlier, cheers to Wak for a very helpful session, nice to get the new machine checked out by someone who knows what to look for!

It also showed up the N75 valve might be a bit iffy but that's another story.


----------



## Gone (May 5, 2009)

Tim G said:


> badyaker said:
> 
> 
> > I picked up my first TT a couple of weeks ago and took it to Wak last night for a checkover and a few specific checks. The manual recommends using 98 RON although the car will run fine on 95 as a minimum. I assumed this was precautionary backside-covering nonsense from the maunufacturer, and decided to run on 95 RON.
> ...


Righto well it's taken me a few weeks to get round to this so sorry for the wait, I hadn't forgotten. A good few tanks of V power have been burned and I did another logging session with Wak this evening. In short, we saw air flow readings peak at 180-190 g/s whereas before it was struggling to make 150; the ignition correction was down at 2-3 degrees whereas on 95 RON it was anywhere from 6-9. Calculated peak power output was 232.5 bhp and she pulls right up to 5000 rpm.

In addition to the V power, the car had also just had a service - oil change, new air filter and plugs so she was in peak condition.

Another note - on the previous log we saw a fair bit of over-boost, i.e. actual boost came out higher than requested across the rev range. With the service and V power fuel, actual boost was spot on. We thought I had an iffy N75, but obviously it's OK.

I haven't noticed much difference in MPG on V power, but it is much smoother. I'll keep an eye on it...


----------



## BLinky (Jul 3, 2009)

09TTSQR said:


> For all it's worth, on my US spec. TTS, the manual states you MUST use super.


US gas < UK gas < German Gas


----------



## therealpigdog (Jul 3, 2009)

Only three tanks into ownership of my TT but will probably stick to putting VPower or other 98/99 RON in based on my experiences with my previous car.

I ran a Smart Roadster so a high revving turbo-charged 3 cylinder 700cc unit - it really noticed the difference between the fuels (after a couple of tanks for the ECU to reset itself) and ran smoother and more economically with the higher octane. My mechanic also reckoned it was better for the engine - something confirmed by my uncle (a retired engineer and former executive for one of the oil companies - he used to be biased but still only runs his cars on super unleaded from the three top brands)


----------



## chrisislost86 (Jul 28, 2009)

I used Supermarket 97ron and did 380 miles did 27.6mpg put Shell V-Power in 99ron and did 400miles and got 29.8mpg. Shell have special stuff in there fuel that lubs the cylinder walls up and valves. And if you want more 103ron buy some Millers CVL Turbo


----------



## Jeffe (Jun 7, 2009)

Shell V-Power in 99ron [smiley=thumbsup.gif] .


----------



## P444UL_R (Apr 22, 2009)

TTS wont arrive for a while so based on previous cars. Premium fuel is more noticeable the lighter the car was.
Most noticeable in a VX220 Turbo. Putting in V power made a huge smile inducing difference in performance.


----------



## DrMikeyLikesCars (Oct 7, 2010)

I had amazing results from using the Tesco RON99 fuel this week.

First tank I have put in and on a trip to North Yorks where it was 25:75 mixed (still had 1/4 tank premium in) I made 30-32mpg. On a 240 mile round trip - mainly motorway with sensible speeds I averaged 37.1 over the first journey (120 miles) and 38.5 on the return journey. When I had the vehicle for a demo driver weekend I did 740 miles of mainly motorway and only averaged 34.5 mpg. I managed close to (if not exceeding) 400 miles from the tank (60 litres I think)

I calculated that as a 25% increase in mpg over the premium, although my right foot is beginning to behave itself now  Given the fuel is only 5% more expensive I will be using Super unleaded as default from now on.

The manual and the filler cap both say RON95-97 for the car.

I also found I'm getting more slippage on the front wheel (even with traction on) with the higher grade fuel when I accelerate - which can only mean more fun 

Car is a Mk II TTS.


----------



## Dash (Oct 5, 2008)

95 RON your car won't be able to run at it's full power, simples.

The TT is intended to use 98 RON but they are required by governments to make cars run on 95 RON.

There are differing brands of Super-Unleaded, just like normal petrol. They contain different additives etc. V-Power is probably the most popular, and it (allegedly) contains lots of lovely cleaning agents that will help keep your car's insides ticking over nicely.

Are you prepared to pay £4/tank for better performance, better fuel consumption (alas not enough to offset the £4) and better engine life?

Personally I've noticed in my last couple of cars a smoother engine on super.


----------



## BLinky (Jul 3, 2009)

Dash said:


> 95 RON your car won't be able to run at it's full power, simples.
> 
> Personally I've noticed in my last couple of cars a smoother engine on super.


+1


----------



## steeve (Jul 8, 2010)

I know its tempting to use the 'good' stuff.
I've always thought that the car seems a little smoother on super.
But MCN checked a couple of superbikes on a dyno, they ran both with unleaded and with super unleaded. They did full traces of BHP and Torque. On both bikes the numbers were ................ exactly the same, for both Torque and BHP.

The reason, apparently' for the identical numbers was that the engine management is so sophisticated it compensates and changes settings to optimise performance.


----------



## BLinky (Jul 3, 2009)

hey there, you got the link to this writeup?


----------



## toonmal (Aug 17, 2010)

Excuse me, but who/what is WAK


----------



## steeve (Jul 8, 2010)

BLinky said:


> hey there, you got the link to this writeup?


I just spent some time trying to find this, I'll continue looking. Their search function is not too good. You have to hit on whatever was in the title.

STEVE


----------



## talk-torque (Apr 30, 2008)

Tests done on other cars may not tell the whole story as far as the TFSi engines go, as I believe adaptation to lower RON numbers, resulting in lower power output etc, due to re-timing, or anti-knock, is a function of the design.


----------



## TT-driver (Sep 14, 2010)

The 200HP 2.0 TFSi was designed with RON 98 in mind, 95 being the alternative. According to Audi, the performance figures can be less using 95. My dealer salesman said it was fine using 95 but what does he know? He never saw the inside of an used engine. 
I think the 211 HP version and the 1.8TFSi were developed for RON 95 and thus may not benefit from 98 at all.

I'm using BP ultimate most of the time anyway. If not for the performance then at least for cleaner injectors and hopefully less sooth in the air inlets. Yes I know the fuel doesn't get there but I'm hoping for less carbon residues as a result from burning the fuel in the first place. Less carbon after explosion is done means less carbon goes through the EGR into the inlets.

The engine does idle better on BP Ultimate.

In a Dutch car magazine they wrote that the sparkplugs of a normally aspirated 2.0 FSI do suffer from not using RON98 fuel. For what it's worth.


----------



## 6andy69 (Jun 7, 2010)

I use normal 95 every day and if im going to have a play or go to a track then 99. Otherwise I cant see spending the extra money for the same mpg.


----------



## keimarTT (Jun 17, 2010)

The following site has a scientific comparison of Tesco 99 vs Shell V vs BP102; basically the Tesco 99 is the best in terms of power and price.

http://www.thorneymotorsport.co.uk/tuning/Fuel_Test_Results_Update.shtml


----------



## Survey S2000 (Jul 28, 2009)

i used super (on the fuel card :wink: )


----------



## Gren (Jul 25, 2002)

6andy69 said:


> I use normal 95 every day and if im going to have a play or go to a track then 99. Otherwise I cant see spending the extra money for the same mpg.


Never put anything other than Super in the TTS but my old Mk1 used to get 10% or so more mpg out of the dearer stuff. Never much saw a change in performance though. Guess I was using less petrol for the same power rather than using my right foot as much.


----------



## BLinky (Jul 3, 2009)

6andy69 said:


> I use normal 95 every day and if im going to have a play or go to a track then 99. Otherwise I cant see spending the extra money for the same mpg.


i dont think just filling up with 99 then hitting the tracks will allow you to gain maximum benefits as the car's system will still have a load of 95 in and the ECU wouldnt have had time to reset. anyways 99 is triple points! ducati penknife = win.


----------



## Matchu (Jul 19, 2009)

Always always Super..........unless I'm desperate.


----------



## BLinky (Jul 3, 2009)

Matchu said:


> Always always Super..........unless I'm desperate.


we do not allow ourselfs to become desperate (for petrol)


----------



## Dash (Oct 5, 2008)

steeve said:


> But MCN checked a couple of superbikes on a dyno, they ran both with unleaded and with super unleaded. They did full traces of BHP and Torque. On both bikes the numbers were ................ exactly the same, for both Torque and BHP.
> 
> The reason, apparently' for the identical numbers was that the engine management is so sophisticated it compensates and changes settings to optimise performance.


If the engine management system was advanced it would take advantage of the higher octane levels.


----------



## DrMikeyLikesCars (Oct 7, 2010)

BLinky said:


> 6andy69 said:
> 
> 
> > I use normal 95 every day and if im going to have a play or go to a track then 99. Otherwise I cant see spending the extra money for the same mpg.
> ...


I'd agree.... there is something bizarre going on with mine.

Filled up with 99RON and on the day achieved 32.5ish
Left overnight and ran a 240mile round trip with 37-39mpg - 1 person, 3/4 tank fuel
Filled again with 99RON and did an immediate run... 29-32mpg
Left overnight and from cold achieved 37mpg. - 4 people in car but low fuel.
Filled with 99RON and did a 520 mile round trip with start stop London traffic (and a pit stop .. obviously) and only achieved 30-33mpg. 4 peeps.

Bit unscientific but there is a big difference with the same fuel over a few trips. Going to try a more scientific approach and record things to try and understand the difference (including average speed, etc.)


----------



## jaybyme (Mar 10, 2010)

keimarTT said:


> The following site has a scientific comparison of Tesco 99 vs Shell V vs BP102; basically the Tesco 99 is the best in terms of power and price.
> 
> http://www.thorneymotorsport.co.uk/tuning/Fuel_Test_Results_Update.shtml


could be very bias as they are partners with Tesco :wink: 
I use Bp 102 ,which is readily available in Germany, in tuned turbo cars.
Not sure I would bother using anything above 98 octane in normally aspirated cars


----------



## MXS (May 10, 2010)

5th Gear did a test on Super fuels not that long ago, and found that Shell Optimax was the best of the bunch, I tend to run on Optimax when possible, or use Tesco if there is not a shell forecourt available at the time.


----------



## Spooks (Jul 24, 2010)

TheDude said:


> wallsendmag said:
> 
> 
> > Once again the search function works wonders.
> ...


Thank you for a really interesting post. Sometimes old posts need refreshing as things change and develop over time.
Don't be offended by the forum Troll every forum has one.
For the record I always use the best petrol I can find regardless of cost.


----------



## 6andy69 (Jun 7, 2010)

jaybyme said:


> keimarTT said:
> 
> 
> > The following site has a scientific comparison of Tesco 99 vs Shell V vs BP102; basically the Tesco 99 is the best in terms of power and price.
> ...


How much is the BP102 in Germany?? I thought it was well expensive when they sold in the UK but they have stopped selling it now.


----------



## Wallsendmag (Feb 12, 2004)

Spooks said:


> TheDude said:
> 
> 
> > wallsendmag said:
> ...


Sorry if I offended your so worthy contribution but the MkII forum is a joke with people asking the same question every week when it's already been answered a thousand times.


----------



## BLinky (Jul 3, 2009)

Prepare youselfs, I'm not saying anything offensive. I'm saying nothing at all! what a pointless post! gg.


----------



## 6andy69 (Jun 7, 2010)

thinking about mpg if the spoiler was down at 80/90ish would this improve the mpg on the motorway?

can vag com allow you to control the spoiler yourself and not been auto?


----------



## keith j (Aug 3, 2010)

6andy69 said:


> can vag com allow you to control the spoiler yourself and not been auto?


I would also like to know the answer to this. It has been asked before on this forum but has always resulted in a debate about the safety aspects of changing the speed that the spoiler raises automatically and I have not yet seen a definitive answer.


----------



## brittan (May 18, 2007)

I recall Toshiba and others answering this question more than once: the deploy/retract speeds cannot be altered in Vagcom (now called VCDS) or in VAS (dealer diagnostic plug in thingy)

A previous thread on the subject:
viewtopic.php?f=19&t=166578&p=1695414&hilit=spoiler+vagcom#p1695414


----------



## TT-driver (Sep 14, 2010)

keith j said:


> 6andy69 said:
> 
> 
> > can vag com allow you to control the spoiler yourself and not been auto?
> ...


If the spoiler could be down at 200km/h and the car would veer off just like this topic did, then who is to blame?
I'd think the chosen speeds are a compromise between fuel consumption/safety/legal speeds/preventing constant flipping up and down.


----------



## 6andy69 (Jun 7, 2010)

also if your on a 1/4 you would prefer the spoiler to stay down too. unless you just remove it for tht purpose. :?


----------

