In my experience, even people whom know how to divide correctly and keep track of distance and volume generally get the economy wrong by 20% or more. Odometers are generally not very accurate, and there isn't much consistency between the full tank shutoff at gas stations.
Both of my cars will often have a huge discrepancy between the odometer miles/gallons from a particular fill and the more accurate calculation from a long term average across multiple tanks of fuel, and using a correction factor for the odometer. A good illustration of this is on fuelly.com. Here is the page for the 190D (the '87 is mine): http://www.fuelly.com/car/mercedes-benz/190d There are 4 190Ds, and you will see that they all seem to vary by about 5mpg between tanks. With my own car, I've tried adjusting this for fuel quality and the type of driving, and found that it doesn't change the variation much- it seems like mostly "random error," probably from the pump shutting off at different levels. Tyler > You're giving him a lot of credit. Its usually "I drove about 100 miles > (meaning 80) and put in about 5 gallons of fuel (meaning 5.8) so thats > about 45mpg" > > Very few people even really know how to calculate mpg, never mind > bothering to use real numbers. > > -Curt _______________________________________ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com