Tesco 99 Ron

[GrayMK5GTI]

.
Apparently, if tuned for V-Power/99 and you have to fill with 95 RON, it will take a good half tankful or so before you will feel the inferior results.

Not exactly. If, due to the fuel, it can't run such high timing, boost, etc it will correct instantly rather than give pinking or knock or leave the engine running at dangerous levels.

That's what these engines do.

Hedge am I right in thinking that although my car is mapped to 99RON (R-Tech custom Stg1) it will still run safely on 95 or 97 RON if that's all that's available (or I fill up on 95 by mistake)? I understand the OEM map is set to 95RON (in the uk) so anything stronger is a bonus. . . 

[Hedge]

OEM map is for 98 or higher as per your filler cap.

Perhaps you should ask Nick what his map would do. My guess is it will run but not optimally.

I'm not sure what the reduced octane will affect timing or boost wise but there will be some changes.

[Geoffcapes]

I always run my stage 2 scirocco on tesco 99 it seems to run better on that than anything else!

[Frodo-anni]

Also with Tesco99 you get tesco points and vouchers which means free fuel, shell dont seem to issue vouchers as often regadless of how much i use.

[pomsteroonie]

I have run every car I have owned with a turbo on Tesco 99 including my 09 GTR and my scooby track car and I am sure I can feel the difference. It also seems to give a few more mpg the Shell but from what I understand the only real differences are that the Shell fuel has more additives in it than the Tescos.

[RedRobin]

.
It seems to me that anyone running a GTI or performance car on the road is best off running it on either Tesco 99 or V-Power but should avoid using any other fuel.

[Tamiyoman]

.
It seems to me that anyone running a GTI or performance car on the road is best off running it on either Tesco 99 or V-Power but should avoid using any other fuel.

My regime is 1 Tank of V-Power (purely for the additives) to 3 Tanks of Momentum 99, that pretty much covers me for 3 months anyway 

[GrayMK5GTI]

OEM map is for 98 or higher as per your filler cap.

Perhaps you should ask Nick what his map would do. My guess is it will run but not optimally.

I'm not sure what the reduced octane will affect timing or boost wise but there will be some changes.

My filler cap says 95RON - although Im not opening that can of worms 

As standard it felt very flat on 95RON so I avoid it like the plaque now it's mapped.

[Hedge]

My filler cap says 95RON - although Im not opening that can of worms 

As standard it felt very flat on 95RON so I avoid it like the plaque now it's mapped.

Can you take a picture. Mine doesn't. 

[AndyS]

I use Tesco 99 all the time , but with a good measure of Redex in every tank  

[gazon69]

OEM map is for 98 or higher as per your filler cap.

Perhaps you should ask Nick what his map would do. My guess is it will run but not optimally.

I'm not sure what the reduced octane will affect timing or boost wise but there will be some changes.

My filler cap says 95RON - although Im not opening that can of worms 

As standard it felt very flat on 95RON so I avoid it like the plaque now it's mapped.

So does mine

[RedRobin]

.
My filler cap label says:



Which I interpret as meaning that you are advised to run on a minimum of 98 RON but may run on 95 if you can't obtain it. All as advised in the GTI Handbook - RTFM!! It says that if you are obliged to run on 95 "in emergency" you should "drive at medium engine speeds and avoid high engine loading". Hence why reputable tuners insist you use at least V-Power or Tesco 99.

[Hedge]

So in the above picture (Ta Robin) it says 98RON / 95ROZ not 98 or 95 RON. 

[RedRobin]

So in the above picture (Ta Robin) it says 98RON / 95ROZ not 98 or 95 RON. 

....I never noticed the ROZ but what's the difference between RON and ROZ? - I can't find anything via Google.

[Hedge]

I could only find ROZ – Research-Oktanzahl - German for Research Octane Number.