car-tco
GitHub对比购车、租车等方案的全生命周期总成本，揭示折旧与维护真相。适用于租赁或购买决策、旧车持有分析，输出真实月成本及假设清单。
触发场景
安装
npx skills add mohitagw15856/pm-claude-skills --skill car-tco -g -y
SKILL.md
Frontmatter
{
"name": "car-tco",
"homepage": "https:\/\/mohitagw15856.github.io\/pm-claude-skills\/skill\/car-tco.html",
"metadata": {
"openclaw": {
"emoji": "🧮"
}
},
"description": "Compare the total cost of car ownership across buy-new, buy-used, lease, and keep-your-current-car — depreciation, insurance, maintenance ramp, and fuel over a real horizon, not just the monthly payment. Use when asked should I lease or buy a car, is it cheaper to keep my old car, what does this car really cost per month, or new vs used total cost. Produces the ranked scenario totals, per-month true cost, the assumption ledger, and the not-modeled list."
}
Car TCO Skill
Cars are sold on monthly payments and owned on total cost — and the two rank options differently. Depreciation (the biggest cost of a new car) never appears on a statement; maintenance (the biggest fear about an old car) is usually smaller than a year of new-car depreciation. This skill compares buy-new, buy-used, lease-forever, and keep-current on the same total-cost basis over the same horizon.
What This Skill Produces
- Ranked scenario totals — every requested scenario over the same horizon, cheapest first
- True per-month cost — total ÷ months, the number to compare against the payment the dealer quotes
- The assumption ledger — depreciation curve, maintenance ramp, insurance deltas, all labeled
- The not-modeled list — financing interest, jurisdiction taxes, reliability luck
Required Inputs
Ask for these if not provided:
- Which scenarios to compare — any of: new price, used-equivalent price, lease terms, current car's value + annual maintenance
- Horizon — years they realistically keep cars (default 8, labeled); short horizons flatter leasing, long ones flatter buying
- Miles per year and rough fuel/energy cost (defaults 12,000 mi / $0.14 per mile, labeled)
Programmatic Helper
python3 scripts/car_tco.py --new-price 38000 --used-price 24000 --lease-month 420 --keep-value 9000
python3 scripts/car_tco.py --new-price 38000 --keep-value 9000 --keep-maint 1800 --horizon 6 --json
Deterministic. Depreciation: 20% year one then 10%/yr for new, gentler for used/current. Maintenance ramps 8%/yr (used cars start further up the ramp). Leases re-lease at each term end with a fresh drive-off. Resale value is credited back — TCO is what you spent minus what you can recover.
Framework: The Payment Illusion Rules
- Depreciation is the invisible line item — a new car's largest cost has no bill; it's the resale-value credit shrinking
- "My old car needs $2,000 of work" is usually cheap — compare the repair to a year of the replacement's depreciation before calling it "not worth fixing"
- Leasing buys flexibility, not savings — lease-forever means paying peak depreciation years forever; price that honestly and let people buy flexibility knowingly
- Margins under ~10% are noise — the model's assumptions can't resolve differences that small; say "roughly a tie," not a winner
- The horizon drives the ranking — always name it; the same inputs rank differently at 3 years vs 10
Output Format
Car TCO: [scenarios] over [N] years
The Ranking
[Script output: totals cheapest-first, per-month true cost]
Reading the Ranking
[Two sentences: how far apart the options really are, and which assumption could flip the order.]
What This Model Ignores
Financing interest (run the loan separately) · taxes and fees by jurisdiction · reliability variance (a lemon breaks any model) · the non-financials (safety features, the want).
Educational model, not financial advice — verify with a licensed professional before acting on it.
Quality Checks
- All scenarios use the same horizon and mileage
- Resale value is credited back in every ownership scenario
- Per-month true cost appears next to the totals
- Sub-10% margins are called ties, not winners
- The disclaimer line appears in the artifact
Anti-Patterns
- Do not rank on monthly payment — that's the illusion this skill exists to correct
- Do not omit depreciation or resale from ownership scenarios
- Do not treat maintenance fears as data — use the ramp, and compare repairs to replacement depreciation
- Do not extrapolate one scenario's horizon onto another (a 3-year lease vs 8-year ownership is not a comparison)
- Do not moralize the want — price the options honestly and let the user choose with open eyes
版本历史
- 54fad50 当前 2026-07-19 12:12
