[houseofdiesel]

I love these little cars, so incredible efficient. I have a 2006 that we bought new in late 2007, pure cabrio, only has 26000kms to date.

99% of the people who are considering one are better served in a VW tdi (early models like 1996-2003), they are slightly less efficient in the city but as good on the highway and have no long term engine issues. The smart is challenged that way unless you REALLY baby it and take exception care of it. Most have a lifter failure in the valve train (of the engine I have seen that were dead locally). Few change the oil properly and leave sludge/residue behind, it has to be sucked out when HOT and even pour a bit of clean and keep sucking to get it all, of the engines I have seen apart-they were filthy inside with large chunks of carbon everywhere on the timing chain side and goo everywhere (dealer serviced that one). High quality fuel is extremely important, the common rail injectors do not like anything else and are not serviceable (dead injectors are common, they just plain wear out and only deliver half the required fuel when worn or worse so hard starting is common). Wiring harness issues are another problem from either water and salt getting in or from the engine vibration (it rocks a lot), the protective sleeve on the harness will chew right through the wires.

I have a lifetime average of 3.1L/100kms on mine (75 mpg US), if I have to go long distance on the highway it gets worse very fast, going 100-105km/h even drafting nets 4-5L range (47-59 mpg). Keeping it at 80-90 nets 3 (78 mpg). City running does not really bother the fuel consumption if you are careful, it is so light. I do sometimes coast and use other techniques but never engine off. These poor little cars work hard and I wouldn't want to coke the oil in the turbo or have other problems.

Chipping it is fine if you are careful with it, otherwise a recipe for disaster. You can get 60hp and 100 torque with a tune, most of them need the waste gate adjusted to prevent overboost and limp mode once chipped. As mentioned, these engine work really hard and are easily overstressed they only hold 2.5L of oil, it gets hot. I have some long term goals to increase my sump and add a bypass oil filter, then maybe chip it!