::: nBlog :::

Last week my Saab reached 500.000 kilometers, still with virtually everything working like it was new. Since last year it has also been certified for Ethanol-based fuel, with stricter emission standards. I have put some extra effort to preserve the car – they don’t manufacture these anymore – but mostly the secret to it’s longevity is my preventive maintenance based on continuous data feed and analytics.

The latest small repair, for instance, was an occasional lean mixture during light acceleration. The car did not turn on the Check Engine Light, but quietly stored the parameters around the condition. Although the car’s computer (ECU) does some waterfall-type analysis itself, this small glitch was just plainly indicated.

A modern car tracks both air and fuel input very carefully in order to burn the fuel as efficiently as possible and to meet emissions standards. A lean mixture, which deviates from the requested value, clearly means that air comes in from somewhere after the Mass Airflow measurement point.

Now as the intake vacuum is used by quite many auxiliary systems like brake booster, crankcase ventilation and fuel tank vapor collection, there are many pipes and joints which can let extra air in when worn out. Furthermore, a turbo engine as this also exhibits positive pressure in the intake manifold, so there’s an intricate network of bypass valves. In my case it was just the crankcase ventilation seal right on the top of the engine, very easy to change.

Now, 16 years after the car was manufactured in Trollhättan, Sweden, I am wondering why car engines have evolved so little since. With today’s availability of cheap miniature sensors, all these components could have them embedded to detect the tiniest deviations from normal operation. While my Saab has 512Kbytes of code and 2Mbytes of RAM, a modern car has easily 100x this. Still most of the new processing power is used for entertainment and not for comprehensively keeping the car in perfect operating shape.

A partial reason is the long-tailed maintenance/spare part business, which benefits when there’s always something to repair. Most car manufacturers don’t want to rock the boat, so they slow down development of certain areas so that the lucratice service revenue keeps coming in. It will probably take a new, disruptive car maker to break this cycle and suddenly offer cars with e.g. million kilometer guarantee. Maybe it’s the Saab raising from ashes after some years.


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