450 Modifications for California compliance?

[smart-*ss]

I have been comparing mileage notes for many months with someone nearby who has almost exactly the same car that I do, his a 2006 and mine a 2005 450 ForTwo Passion Cabrio. The only difference is that his car is apparently U.S. compliant only, and mine is certified for U.S. and California. We both use the same brand of gas, have our tires inflated to 39-42 psi, have about the same driving habits

He consistently gets at least 10% better mileage than I do all the time, and just told me that he got 87 mpg on a highway trip. My best ever was just under 44 mpg, also on that same highway trip. My average so far (during this past year) has been 32 mpg.

G&K, who modified these cars for the U.S., told me that they did nothing differently for California cars, but I strongly suspect this is not true.

Does anyone know exactly what could be different between our cars that would make such a difference in mileage?

[rgaus]

Hi smart-*ss,

I'm Ron Gaus, in St. Louis. We've been distributing smarts to customers around the country for about two and a half years and I've determined that there are some smarts that just seem to get better mileage than others. Not sure why. I have a good friend in Kentucky that swears he averages 55mpg every single tank. That's incredible to me, as my experience has averaged more in the low to mid forties. I do know, through many experimental drives over the last few years, that your top mileage figure is over 50mpg in any of these cars if you keep the car at 55 to 60mph on the highway only, for 100 to 200 miles. We've done that at least four different times. Going over 60 mph will begin to severely cut into that figure, however. I do know that there can be wide swings in results depending upon the slope difference of the pavement on two successive fills. I once filled my smart on one side of a pump with a noticable slant, then pulled to the other side, facing the opposite direction, and added another gallon! That will make a huge difference on "apparent" mpg calculations.

Here's a suggestion for your unique situation. Trade cars for a week if he'll do that. Meet at a gas station and fill your cars up. Slow fill on the pump. Note your exact location next to the pump. Meet at that same gas station a week later, same pump, same side, same direction, same spot. Fill your cars in the same manner. See if your car still gets the lower gas mileage or if his car now gets the lower gas mileage. It could be in how you drive your cars instead of unique engine differences. That experiement would reveal it. Good luck. The best thing about the smart is it's style. Gas mileage is the gravy. If it's your driving style, have him give you hints on how he drives. Might something simple.

Oh, and regarding the California cars having different emissions settings, they don't. G&K told you correctly. All converted smart cars would pass California emissions standards, but they still have to go through a separate testing. The reason for that is G&K would have had to pay an enormous fee as a "manufacturer" to have all their cars exempted from the emissions test. There simply weren't enough cars to be sold in California where that was economically feasible. The only other option was to test each California car separately for the emissions portion. That's what was done.

Ron Gaus, aSmartCar.com, St. Louis