Tesco 99 RON

[robwright]

I was at the pump in Tesco earlier treating my car to a tank of 99 RON when I thought hold on didn't someone (I think Scott) say that Tesco high octane is mainly bio ethanol and not good for our cars. Naturally I stopped where I was at half a tank. Question is how to find out if it is mainly bio ethanol and indeed what damage if any could be done?? I am no petrol expert and a trawl of the internet has mainly turned up chat forums lol!!

 

[Diver944]

Lot's of us have used Tesco 99 for a number of years and so far I haven't heard of any problems. The potential worry is that it's formulation may cause problems with the rubber seals and pipes in the system. Again I haven't heard of anything yet

 

[robwright]

I must admit the half tank I have put in does feel nice [] I am an old skin flint really and like to the clubcard points from petrol, of which obviously I am earning more of now that I own a 944 lol. I did trawl hard but couldn't find anything derogatory about it. I have had plenty of good info from Scott in the past though and believe him to be quite reputable so thought I had better ask the question.

 

[Diver944]

ORIGINAL: robwright

I have had plenty of good info from Scott in the past though and believe him to be quite reputable so thought I had better ask the question.

He is and he has the background for it too and knows a lot more about some of the technicalities than I ever will (that's a pint you owe me Scott [])

However he sold his car so we must all pillory him at every opportunity []

 

[robwright]

And mine's a Fosters too Scott []

 

[997GT3_KO]

I too have noticed the 99RON Super Unleaded at TESCO's pump ... very tempted myself ...

 

[944 man]

Greenergy super unleaded is 10% bioethanol. In my experience it suits turbos better, where the benefit from the greater knock resistance exceeds the loss through the lower calorific value.

A normally aspirated 944 will benefit from Shell V-Power more, I feel (and it wont cost any more as youll see more miles to a tankful).


Simon

 

[zcacogp]

ORIGINAL: robwright

And mine's a Fosters too Scott []

Mine's a pint of the old-git ale they have on draught. The more old-gittish the better (with some twigs in for added effect.) []


Oli.

 

[Mike_Pollock]

Have been trying different petrols recently Tesco 99 is next and as Simon says my N/A 2.5 loves V Power best, so far.....
Tesco next fill up is actually the closest too me but not the easiest to get to.
Mike

 

[barks944]

ORIGINAL: 944 man

Greenergy super unleaded is 10% bioethanol. In my experience it suits turbos better, where the benefit from the greater knock resistance exceeds the loss through the lower calorific value.

A normally aspirated 944 will benefit from Shell V-Power more, I feel (and it wont cost any more as youll see more miles to a tankful).


Simon

The point you are making about getting more miles to the tankfull is somthing both my dad and I have noticed. Although what I cant explain is why that is the case, what is it about shell v-power that gives an economy benefit. It cant be the octane rating can it as the lux has no knock sensor.

 

[Mike_Pollock]

You get more power so you dont put your foot down as far?

Doesn't work for me as I usually drive a dieset van, so the throttle is an on/off switch!

Mike

 

[barks944]

Why do you get more power?

 

[Eldavo]

I printed off a £1 off voucher for v-power off the website. Click on the consumer section and there is an advert for it at the bottom of the page.

 

[robwright]

Well took my turbo and it's half tank of Tescoo 99 RON for a run to London and back today for work. So the result?? Well in the words of Louis Walsh - I liked it!!! The car seemed to respond really well to the extra RONs. Especially when cruising at about 80 in 5th. The power delivery seemed very good, smooth and instantaneous when I put my foot down. Of course I could have imagined all of this but I am convinced I didn't. I'm sold!!!

 

[Mike_Pollock]

Well,..... my theory is that if you inject the same amount of two different fuels 1 having more hydrocarbons than the other you will get more power out of it (assuming there is enough oxygen).
My alternative theory is that because you get a crisper, quicker burn and because of this, it is timed more exactly to hit the piston down at the best possible time.

Exactly why has been discussed several times on here, with loads of obvious, techinical and slightly strange ideas!

However, almost all agree that their car runs better on the V-Power, exactly as Shell say.

It does.

Mike

 

[Mike_Pollock]

NB - my car says on the filler cap that it requires 98RON. so on 97 it should not be running properly
Mike

 

[davidcross]

I use tesco 99 ron on my 997s and not had any probs but im keen to know if there is anything i shud look out for longer term.

 

[robwright]

ORIGINAL: Eldavo

I printed off a £1 off voucher for v-power off the website. Click on the consumer section and there is an advert for it at the bottom of the page.

I had a look but couldn't find that voucher. Any chamce you could post a link mate?

 

[Eldavo]

Only reason I didn't post a link before is that I do most of my browsing and posting via my Iphone and it didn't want to play ball.

LINK: Shell V-Power Discount Voucher

 

[sawood12]

ORIGINAL: robwright

I must admit the half tank I have put in does feel nice [] I am an old skin flint really and like to the clubcard points from petrol, of which obviously I am earning more of now that I own a 944 lol. I did trawl hard but couldn't find anything derogatory about it. I have had plenty of good info from Scott in the past though and believe him to be quite reputable so thought I had better ask the question.

Sorry to have caused you some worry mate, I wasn't 100% sure about Tesco fuel and my comment was intended as more of a query than a statement of fact. I didn't realise that so many people use it. I know from the products the company I work for produces where we have been experimenting with high % bio-fuels (about 25%) that they are very corrosive to conventional rubber seal materials and you have to use different seals. Clearly the Tesco fuel is either of a low enough content for it not to be an issue or the type of bio-fuel they use is not as corrosive as the stuff we have been using.

RON value relates to the knock resistance of fuels, the higher the RON value the higher the knock resistance. Provided you have an ECU or mapping that can exploit the extra RONs then the reason you either get better fuel consumption or better power (you can't have both, you can only trade one for the other) is because you can advance the timing more before knock is detected, therefore you get more compression per bang therefore more force from the expansion of the gasses in the cylinder which means more torque leading to more power. So yes - at the same RPM and same throttle postion you could be getting more power - or conversly the same power at lower RPM and less throttle position. I've seen a plot from the knock sensor on a stock ECU on another forum and the knock detection system on the turbo's and S2's is very active - it is not merely a safety net, it is an active closed loop system that under certain conditions is actively managing the ignition timing upto the knock limit.

I'm not so sure that if you notice a difference with 99RON fuel you are actually exploiting the extra RON's of Tesco fuel, but probably getting the full RON's you are mapped for. Unfortunately the fuel you buy is most likely a lower RON value than advertised for a number of reasons - shelf life, contamination etc. so by using 99RON, you are ending up with more RON's than standard fuel and most likely getting closer to the RON value your ECU is mapped for.