Quote:
Originally Posted by Julian Edgar
Here I am back again - only just saw this thread.
I agree that an A/B/A test would be more valid than what I have done.
But also a bit more on the background. I live 80km (50 miles) north of Canberra, Australia. I drive into Canberra and back 2-3 days a week. There is no traffic - I don't even reach a traffic light until about 75km into the trip. Sometimes I see only 5 cars in the first 50km.
It is just an empty country road driven at a constant speed - 100 km/h.
I also drive from here to Sydney and back - freeway all the way (it's about 250km each way, with only the final part in city traffic).
I owned the car for about 10 months before adding the vortex generators.
I know the fuel economy on these trips very well. I can immediately see by the fuel economy if my wife has filled with 95 versus 98 octane, and I can see the difference in fuel economy that my 0 degree C mornings are having. (40 degrees C in summer, 0 degrees in winter.)
The fuel economy has never been as good as with the vortex generators fitted. Never.
Now: here's the joy for you sceptics. I had a cam belt change at 100,000km, about 2 weeks after I fitted the vortex generators. I saw the improvement in fuel economy straight after I fitted the VGs, but the confirmation over the 10,000km since has been with the cam belt changed and the VGs fitted. So perhaps some of the improvement is that cam timing is changed a fraction, i.e. belt stretch is no longer there? To me it doesn't seem likely, but it is possible.
Oh and the kit price people are quoting is for heaps of the things. I think mine cost me a few dollars each - but I did buy them years ago.
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Julian,forgive me,as I'm quite late to the party,but can you please tell us the kind of car you're driving?
My mind was thinking in the direction of a notchback.I wanted to make sure.Thanks!