I only got 37 mpg on this tank. 90% highway

[crashdiva919]

do we all forget that cars have a break-in period?!?! you will get closer the more you drive your smart! duh! so drive your smart!!!!

[RVGRINGO]

We noticed that our mileage was dropping off a bit and the car felt a bit sluggish. I checked the tires and found them down to 21-23 lbs/sq in. I pumped them up to 35 lbs and, WOW! So much less rolling resistance that it was obvious; it even steered much easier. I'm sure we'll be back to 43-50 mpg again. (Yes, ours has the Mercedes Turbocharged engine, 698cc).

[crashdiva919]

it's a turbo charged engine? su-weeet!

[RVGRINGO]

It is, and we love it. Note that it is a 450, purchased in Guadalajara in the fall of 2006. It now has 16700 happy kilometers on the odometer and has had its first oil change and warranty service at 15000 without incident. Since warranty will be expired by the time it needs an oil change at 30000, I must remember to find and buy an oil extraction pump. That little engine has no drain plug and must be pumped out through the dip-stick hole; a bit of an inconvenience, but a practical one for any aluminum alloy engine.

[jwight]

RV, check out eBay - somebody is modifying the 450 oil pans by adding a drain plug.

Update - can't find that item on eBay now or via Google; guess no longer available.