Monday, January 19, 2026

Car maintenance tips

See? You can keep a car running a long time.

The other day, I became obsessed with a batch of YouTube videos in the How-to-make-your-car-last-for-300,000-miles-or-more genre. These good populist YouTube patriots are here to help us thwart the corporate conspiracy to make us think modern cars should only last for 150,000 miles.  Here are some of the more frequent recommendations, starting with the ones that are easiest, free, and couldn't hurt. If you want to know why these things are good, you'll have to watch the videos yourself. 

1. Apply the emergency brake before putting the shifter in park on an incline (assume every parking spot has an incline).

 2. When starting in cold weather, let the car run for just 20 or 30 seconds before driving away. Idling is bad for engines.

3. Anticipate stops so you don't have to jam on the breaks. 

4. Use only Top Tier (high detergent) gasoline. Apparently it's sold at Shell, Chevron, Mobil, Sunoco, and Valero (near us in Twin Mountain and Lancaster). Look for this logo on the pump: 

 

4. Never "top off" the gas tank.

5. Don't let the gas tank go below one-quarter full.  

6. Check battery connections and clean any that are corroded.
 
7.  Change oil more frequently than recommended, every 3-4,000 miles (5,000 if you do mainly highway driving). 
 
8. Use only high quality synthetic oil and high quality oil filters. 
 
Now we're getting into things that might cost you some money and could, I suppose, do more harm than good.  I am merely passing on these things, so don't take my word for it--ask your mechanic, or watch the videos yourself.  
 
9. Add a PEA-based fuel-injector cleaner to the gas tank when you get an oil change. One of the YouTubers recommended Amsoil P.I. ($17).  He also mentioned BG 44K ($24) and Royal Purple Max-Clean ($12). Heres what AI said about those two:  "BG 44K is often seen as a professional-grade, heavy-duty cleaner for significant restoration, while Max-Clean offers a synthetic blend for cleaning and stabilization, with BG 44K generally considered more potent and expensive, making it ideal for deep cleaning every 6-12 months versus Max-Clean's more frequent use."
 
10. Change your air filter with every-other oil change (this used to be easy in old cars).  
 
11. In snowy climes, get an undercoating or wash the road salt off once a week in winter.  AI undercoat cost estimate: $300-$1000.  (I'm skeptical of this advice, so I consulted AI for more insight. See below. 
 
12. Change Transmission fluid every 50,000 to 60,000 miles. Careful here.  In some cases it's best to do a Flush $250-$400); that might be bad for some cars, which only need a drain and fill ($150-$250).  CVT  transmissions (like my Honda fit) need more frequent fluid changes. This is expensive, but we've had a couple of Hondas whose transmissions wore out around 200,000 miles and maybe if we'd changed the fluid . . . . . (Manufactures don't tell you to do this so you'll have buy a new car at 150,000 miles, hence the conspiracy). 
 
13. Flush and refill the coolant every 3-5 years. 
 
NOTES
 
Here are the videos in case you want more details, explanations of why these things are important, or the recommendations I left out.  
 
 
Proven habits that will make your car last over 500k miles without repairs This one has 15 recommendations, some of which I didn't include above. 
 
 
Gemini on washing cars during cold weather: 
 
The short answer is yes, you should wash it, but you need to be strategic about how and when you do it.

While it feels counterintuitive to wash a car that will get salty again the moment you drive away, leaving road salt on your vehicle for extended periods is far more damaging than a fresh layer of salt. Salt accelerates rust and corrosion, eating away at your paint, clear coat, and undercarriage—even in freezing temperatures.

Why You Should Wash It (Despite the Conditions)

    Corrosion "Reset": Even if your car gets dirty immediately after leaving the wash, you have removed the heavy, accumulated crust of salt and sand from the undercarriage and wheel wells. It is this buildup that holds moisture against the metal and causes the most rot.

    Temperature Fluctuations: Salt is most corrosive when the temperature rises slightly (even if it’s still near freezing) or when the sun hits the dark paint of your car, melting the ice/salt mix.

    Visibility: Salt spray severely reduces visibility on windows, mirrors, and headlights.

The Risks of Washing in Freezing Temps

The main danger is not to the paint, but to the mechanisms:

    Doors freezing shut.

    Power windows getting stuck.

    Locks freezing.

    Trunk latches seizing.

Best Practices for Sub-Freezing Car Washes

If the temperature is below freezing (<32∘F or 0∘C), follow these rules to avoid issues:

1. Pick the Right Type of Wash

Avoid driveway washing with a hose. Instead, go to an automatic car wash with a high-powered blow dryer. The drying cycle is crucial to blast water out of crevices before it turns to ice.

    Note: Ensure the car wash offers an undercarriage flush. This is the most critical part of winter washing.

2. The Temperature Threshold

If possible, wait for a day when the temperature is 20∘F (−6∘C) or higher. Below this temperature, water freezes so instantly that it can be difficult to dry the car effectively before ice forms.
 
3. Immediate After-Care (Crucial)

As soon as you exit the wash, do the following:

    Dry the Jambs: Park immediately and use a microfiber towel to wipe down the inside of the door jambs and the rubber seals (weatherstripping) on all doors and the trunk. This is where water traps and freezes doors shut.

    Work the Mechanisms: Open and close all doors, roll the windows down and up, and pop the trunk and fuel door a few times to break the surface tension of any remaining water.

    Check the Wipers: Ensure your wiper blades aren't frozen to the windshield.

4. The "Garage Trick"

If you have access to a heated garage (or even a slightly warmer underground parking structure), go there immediately after the wash. Letting the car sit in a warmer environment for 30–60 minutes allows the remaining water to evaporate rather than freeze.

One Exception: When to Wait

If the temperature is extremely low (e.g., below 10∘F or −12∘C), you might want to wait. At these extreme temperatures, the chemical reaction of salt corrosion slows down significantly. You can usually safely wait for a slightly warmer day without risking rust.

Summary

You aren't washing the car to keep it "clean" in the aesthetic sense; you are washing it to manage corrosion. A dirty car with a fresh, thin layer of salt is better than a car carrying three weeks of caked-on salt mud.

Would you like me to recommend a specific type of rubber protectant spray that prevents your doors from freezing shut after a wash?

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