[aerohead]

Some members are getting discouraged with mods,and I've been thinking of foibles that could be associated with the "magic" of the Scan-Gauge.------------------------------ The "up-shot" of the electronics is that they give instantaneous readings,without burning alot of fuel for results.---------------------------------------- One concern,is that "scanners" may be seduced into taking readings before their vehicle is in a position to provide useful data.-------------------------------------- Here's the rub.A vehicle requires 22-miles (35.5 km) of continuous driving before it reaches equilibrium temperature.------------------------------ Tires will come up to temp in about 5-miles (8 km ),however,coolant,engine oil,transmission and differential require a full 22-miles before their viscosity reaches it's final status.--------------------------------------- Any testing conducted without the "warm-up" has the potential of such a great amount of variables as to render results,dubious at best.-------------------------------- "Ideal" testing,is conducted at 75-degrees F,no wind,flat road surface,no turns,and "special" lubes".( don't ask!).--------------------------------------- City vs highway mpg can vary by a factor of 100%.--------------------------------A 4-mile cold start test could show 40% below your actual mpg.----------------------------------------A 2-mile test could show 55% below your actual mpg.---------------------------------- A 1-mile test could show 75% below your actual mpg.----------------------------------- Wind can effect mpg by (negative) 17%,to (positive) 19%.---------------------------------------- Road grades can effect mpg up to 55%.------------------------------ Rain can cost 1 mpg.---------------------- A 50-degree F test day will cost you 5% mpg.If temp drops to 20-degrees,your looking at a loss of 11%.It's easy to lose 3.5 mpg during any winter.------------------------------------- I hope everyone is tracking "tank" mpg,to go along with their Scan-Gauge results.--------------------------------- I'm not into anybody wasting any additional fuel during testing,but there's a reason for the warm-up,and I'm afraid many modders will suffer needless disappointment if they inadvertently stray from the rule-book.