Dads are near-mythical fonts of knowledge to a child, and it's only with age that we realize that much of that information might not have been accurate. Some of it was simply regurgitated from the ramblings of previous dads, some of it is a massive over-generalization based on some small kernel of truth, and some of it was fabricated to mess with you or get you to behave.
Ahead of a much-deserved Father's Day, I'd like to debunk several myths related to dads and cars:
I've heard a lot of funny ones about high-octane fuel. I've heard a number of people who thing premium fuels will make their car, that only requires regular fuel, run cleaner/faster/smoother. I even knew one young lady whose father had told her that once a car had had high-octane fuel it would somehow damage the engine for it to go back to regular. She thought her Toyota Camry was somehow now a 91 Octane junkie because she accidentally hit the wrong fuel button one time.
Putting high octane fuel in a low compression engine does nothing measurable. High performance engines will suffer mightily from low octane fuel. Exceeding the requirement, in a vehicle that isn't made to take advantage of high octane fuel is just an expensive placebo.
3,000 Miles or Never
“Make sure you change your oil every 3,000 miles or your engine will explode and kill kittens!” your father might have said. This may have been a decent rule of thumb when Pops got his first car, but those days are long gone. At the time even, it was just a rule of thumb. The actual oil life of a vehicle is determined by a wide range of factors like milage, driving style, weather, oil quality, etc.
Today's cars can often manage 5,000 to 10,000 miles between oil changes, and my Fit usually only needs an oil change every 12,000 miles. The real trick is to check oil viscosity regularly, and change it when it has genuinely outlived its usefulness.
New Cars Are Death Traps
A number of people seem to be under the impression that new cars aren't safe because they crumple in an accident. “Old cars were made of steel, and that meant they were strong. By the way, I'm selling my '57 Bel Air to buy a Prius; you interested?”
The truth is that modern cars are specifically designed to absorb an accident's energy by deforming in all the places where there are no people. Old cars just whip the people inside around like gummy bears inside a cocktail shaker and then deform wherever they please, shoving a steering column (probably not collapsible) through dad's skull. I'll take my modern car, thank you very much.
While we're at it, the Compact segment also has more IIHS Top Safety Picks than any other segment, so there goes another tangentially related argument.
It's Illegal To Drive With The Dome Light On
Nope. There are tons of laws regulating which exterior lights motorists have to use or not use in various situations, but virtually nothing on interior lights. It is rather annoying to drive with the dome light on, so somewhere in your bloodline someone probably just said it was illegal in order to get the kids to stop arguing and it stuck.
That said, some cops will pull you over if you're cruising with your dome light on, as it's weird behavior and could mean that you're drunk or stupid enough to be reading and driving.
You Have To Let Your Car Warm Up Before Driving It
“If you want your engine to not tear itself apart in just 10,000 miles, you'd better let that car warm up for a good five to ten minutes before driving it.” Dad never offered an explanation, but he made sure that you knew this was important.
The idea behind this is that warm oil is less viscous than cold oil, and that it pools when the car is sitting. The pooling works itself out very quickly in a working engine, and the viscosity of modern oils is much more consistent than that of older oils. It's not a good idea to hit the race track at maximum revs before reaching operation temperature, but your morning commute is certainly okay.