Millers VSPE 500ml - This stuff works!! I'm running a stroker 1955cc air cooled VW with dual twin choke 40 IDF Webers and this additive vastly improved performance! Where it used to splutter off the stops and seem to be strangled at higher revs, this additive has improved the performance across the rev range! I'm generally using 97 fuel which used to pink under load. No more pinking with this additive! I have no affiliation with Millers! It's worth the money if you are running a warm tuned engine with no ECU.