I have noticed that after a few hours or more of inactivity, the engine of my 2010 Opel Corsa OPC presents idling problems. The engine splutters and the revs are erratic, but after a few minutes the problem seems to go away. I don't notice any clear pattern such as outside temperature, time of day etc, except for the fact that the condition only seems to happen when there have been a few hours of inactivity or more.
GMSA has advised me that this is a problem relating to the poor quality of fuel that we have in South Africa. The Corsa OPC was designed and tuned for 98 octane fuel but the general public only has access to 95 octane. The quality of our fuel is much lower when compared to regions like Europe and North America. GMSA also advised that while there are no effective counter measures at this time, the idling/spluttering problem will not cause any damage to my vehicle.
I have also noticed that the Corsa OPC consistently performs below the manufacturer's claims. One of my associates recommended that I use octane boosters as a “band aid” solution. This seems to imply that both the idling and the performance problems are directly related to the low octane of our fuel even although one problem is transient while the other is pervasive.
My question specifically concerns the matter of octane boosters. There is a lot of confusion, hype and misinformation out there. What is the truth about octane boosters? Do they really work, and can they damage my car in any way?
JASON DALE – By e-mail
The experts we have consulted maintain that the only difference between our ULP and the European version is a small amount of extra sulphur in the local petrol. The normal octane rating in Europe is 95, but 98 is available in some areas.
The octane rating only comes into play at close to full throttle conditions, so that the actual value cannot affect the idling. We believe that manufacturers are often too quick to blame the fuel, and in this case we suspect a software glitch. The lack of performance is something that GMSA should be able to sort out. The industry does not recommend octane boosters because they contain metal compounds that could damage engines.