Yes, I know it is a strange comparison, right?
Linux is powerful!
If you are not aware, Linux is an extremely powerful operating system. Often times, even people who use Linux regularly, have not even begun to tap into all that it has to offer. Linux has all the Horsepower you need for just about any task, just like a diesel engine.
Linux is long lasting!
I have a truck with a Cummins diesel engine that currently has 360,000 miles and I am looking forward to driving it for at least another 150,000 miles. Linux servers in some cases run for many years, without needing to be messed with at all. Linux servers can run for years, without even being rebooted.
Linux is dependable!
When you can't depend on anything else to work, you can depend on Linux. It doesn't mind being worked hard and pushed to it's limits, it just keeps on providing long lasting, dependable service, just like a diesel engine.