can 97 ron be causing all my problems.

[schesterg]

Hi all I have posted a few times about the rough jerky running of my vw scirocco. I decided for the first time to put standard unleaded in from shell not for any particular reason and to my amazement the rough running has pretty much vanished. I tried some high octane, tesco momentum and back to square 1. Il refilled with standard shell and no issues. Can high octane fuel really be the culprit for the overly sensitive pedal, jerky running below 1500 rpm and in traffic and the general lumpiness? It's so much smoother like it used to be when I first bought it.

[pedrotsi]

Its highly unlikely unless your local momentum is actually horse pee. The difference between 97 and 95 shouldnt impact the roc.

I run mine on everything from 91 to home brewed super octane, even 95 gasohol if i cant get regular petrol and it runs fine on everything accept diesel.

[blower]

My CAVD 160ps has a better idle on Sainsburys 97 super unleaded and normal Shell 95.
On Tesco momentum or Shell V-power the idle is noticeably less smooth with slight intermittent juddering felt thru the seat (although no misfires logged with VCDS live misfire counters)
This is only at idle though, regardless of fuel it runs fine when driving round.

[schesterg]

Mines back to square 1 running lumpy and jerky between gear changes and terrible in traffic. I have no I dea what to do. All I can say that it is the worst car iv owned and i have had alot! Been to vw numerous times and they say there is nothing wrong with it. Thier latest excuse is that it's because it has a sporty clutch which tend to be jerkier. S*** is an understatement. Time to sell I think and forget vw forever. Plenty of better cars out there I'm sure. Shame as I liked vw.

[blower]

Somethings not right there - when was the last time the spark plugs were changed? (and did VW do them or 3rd party....thinking wrong plugs here, or should I say wrong plug gap)

[xjay1337]

You should be running 99 octane where possible. It is proven on the dyno on both TFSI and TSI engines to produce more power, run more smoothly and actually more economically.
Shell V-Power is my preferred but 99 Tesco may be more easily available.

[salsajoe]

You should be running 99 octane where possible. It is proven on the dyno on both TFSI and TSI engines to produce more power, run more smoothly and actually more economically.
Shell V-Power is my preferred but 99 Tesco may be more easily available.

My preference is also shell but Tesco 99 so much cheaper at present so every 4th fill is nitro at the moment as think the shell has better detergents IMO (from looking at the exhaust carbon build up) but may be wrong.