I filled my blob STI with Tesco 99 RON for the first time on Sunday. It may be my imagination but my car definitely seems to like it. The throttle response seems better and it seems noticeably quicker.

Am I imagining this or does 99 RON really make much of a difference?

Until about a month ago I always filled my car with V-Power but my two nearest Shell stations both closed recently so I've been using Esso 97 RON for the last few weeks.

 

Some seem more temperamental than others mine hates tesco but loves v power

Always seems crap on cold start on tesco.

 

Mine loves tesco 99, no problems at all and certainly feels more responsive than when I've used esso 97

 

With 97 Ron the ECu will pull some ignition timing to stop det. On 99 Ron it will allow full timing so the engine will be more responsive. I normally run on Tesco 99 as I fill up when shopping.

 

Although my car was mapped with V-Power it runs every bit as well on Momentum with no more activity on the KS3 meter.

JohnD