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Old 03-13-2014, 12:56 AM   #44 (permalink)
paulgato
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Join Date: Sep 2013
Location: Oxford, UK
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Quote:
Originally Posted by PaulB2 View Post
I have my doubts testing tells you anything, at least these short runs. There are just too many variables. Wind can change significantly in a short time. If I were you I'd take my long term data, several tanks or several months, and then compare that with the test version equally long. Or just assume the pan is going to be worth it and don't worry about proving it!
I see your point PaulB2, but most of us are going to be trying several different mods over a several-month period, so waiting a long time is also not a great way to tell if a single mod is helping. Also, mpg changes a lot with the seasons, so you'd really have to run the test over a whole year (or two!) to take account of that. And then over a long period like that so many other variables creep in such as age and wear levels of the engine, different tyres, different driving patterns, etc. etc. so waiting for several months/years and for several re-fuels is not a practical way of testing individual modifications, especially if they are expected to have rather small effects.

ABA tests, or even AAABBB tests, can be useful if repeated enough times. Certainly choosing a very calm day for testing is essential. For example, I found that I got a rather small improvement in mpg by adding 0.1% acetone to my diesel tank at fill-up. The improvement was only in the region of 2% but was repeatable. Obviously I could not do an ABA test (can't take the acetone out of the tank!) but repeated AAABBB tests confirmed the small improvement. But if I had not ALSO felt an immediate subjective increase in power I would not have bothered continuing with it or bothered doing the testing. Sometimes you can just FEEL that something has helped.
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