I drove about 550klm today in a very noisy baja.I was almost empty and i put half a tank of 98 bp fuel in her and by the next set of traffic lights she had developed a flat spot where you had to feather the throttle to try to drive out of it.
On the way home i again almost empty filled her up with the cheapest unleaded and again almost immediatly the hesatation/flat spot was gone? Any ideas?

too high an octane for the way its been tuned maybe what has it been run on before this

It usually just gets the 92 rated fuel

then just run 92 in it.

usually with the 98 u can run the timing a little more advanced. which is what i do.

98 doesn't evaporate as quick, and burns slower - hence the flat spot. No problem in a knock-sensed car, no good in a carby-fed low-comp donk like a VW!

[ Edited on 17-6-2006 by VWCOOL ]

unless the timing is adjusted

and high comp?!

My Bug loves 98 and 100 octane... :P

As long as it's tuned for higher octane it's no problem to run 98. Timing is critical as others have mentioned.

I run 98 octane in My Beetle....

No Problems....

Lee