Over time vehicles will lose some of their performance. This has a direct impact on their MPG which would lead to an increase in gas usage. Many drivers even miss these tune-ups when they have an annual service and only put things right which are a necessity.
In San Diego Ca, there is no reason for any driver to not have an engine tune-up at any time because we will take the service to them. Finding a reliable garage is hard enough when there is limited time during a working week.