WTFAQ?

Archives: Cards

  • Why does my check-engine light come on when nothing seems wrong?

    Most common Loose gas cap. The evaporative emissions system detects pressure changes; a loose cap looks like a leak. Tighten it, drive 50 miles, light goes out. Second most common O2 sensor or mass airflow sensor reading marginal. Costs $30-150 to replace. The car runs fine; the light is the only symptom. You can drive…

  • Are EVs cheaper to own, really?

    The math Home charging is $0.04-0.10 per mile. Gas is $0.12-0.20 per mile. Insurance is roughly equivalent. Maintenance is genuinely cheaper — no oil changes, brakes last longer due to regenerative braking. The catch Public DC fast charging is $0.20-0.40 per mile. If that’s your only realistic option, the gas car is competitive on lifetime…

  • Does premium fuel actually do anything?

    What octane is Resistance to knock (premature combustion under compression). Higher octane burns later. Useful for high-compression engines like turbo or performance. Pointless in low-compression engines. The myth Premium ‘cleans’ the engine. All gasoline meets the same baseline detergent standard since the EPA mandate in 1995. The ‘cleaning’ claim is marketing copy from the 80s.…

  • Should I tip on a coffee?

    The history Tipping in the US was historically for table service. Counter service (coffee, fast food, takeaway) was below the line. Bartenders sometimes, baristas no. What changed Square + Toast added tip prompts to every transaction starting around 2020. Suddenly every counter is a tipping question. The norm is being rewritten in real time. A…

  • Is buy-now-pay-later actually free money?

    When it’s free Four equal payments, paid on time, no interest. Genuinely free money compared to a credit card. Klarna’s ‘pay in 4’ is the cleanest version. When it’s a trap Miss a payment by one day, retroactive interest on the original amount. Sometimes also a late fee. Affirm has tiered offers — read the…

  • Why are eggs $9 again?

    The supply hit Each major flu outbreak culls 5-10% of the US laying flock. Replacement birds need months to mature before producing. Until then, supply just isn’t there. Why prices stay high Eggs are inelastic — people buy them no matter the price within reason. Producers have no incentive to absorb costs when demand barely…

  • Why is everything called a ‘subscription’ now?

    The business case Predictable monthly revenue is cheaper to finance and more valuable to investors. A $10/month sub is worth more than a $200 one-time sale on the company’s books, even though you paid less. The trick Annual price increases of 5-10% are invisible to most users. Same product gets 50% more expensive over five…

  • When should I actually call an electrician?

    Safe to DIY Replacing a switch, outlet, or fixture, after killing power AT the breaker AND verifying with a non-contact tester (around $15). Use the tester. Always. Always electrician Anything inside the breaker panel. Pre-1970 aluminum wiring. Repeated breaker trips on the same circuit (means a short somewhere). Anything inside a wet area without a…

  • Is WD-40 the right fix for everything?

    What WD-40 actually does WD stands for Water Displacement. It’s a thin solvent that pushes water away. Brilliant for ungluing rusted bolts. Terrible for lubricating moving parts long-term. Why people misuse it It DOES lubricate briefly, then dries out. Squeak comes back in a week, you spray again, and the cycle hides the problem. The…

  • Can I really fix a phone screen with toothpaste?

    What it actually does Toothpaste contains mild abrasives (silica, calcium carbonate). Buff a microscratch in the oleophobic coating? Maybe, briefly. Buff a crack in the actual glass? No. When it backfires Cracked screens have moisture seams. Pressing wet abrasive into them spreads the crack and damages the digitizer underneath. Now your screen is worse AND…