Criteria for Buying a Used Car: A Prioritization Example from 2021

Harshal
9 hours ago
4 min read

Framework to define your preferences, then filter.

I often get asked how I bought a car or what criteria I used. I had already written these criteria down for my own purchase. Turning it into a post does two things: it shows a worked example of prioritization, and it gives one link to share so friends get a clear explanation instead of whatever I remember on the spot.

The approach is to first decide what features you want, in descending order of priority. Use that list to filter options and to know what you can compromise on. Below is the list I used (Ireland, used car, 2021), grouped into three tiers. You can copy the structure and swap in your own priorities.

I spent 60 minutes writing this based on the document I used in 2021. You need 3 minutes to read this.

Context for preferences

At the time of this purchase in 2021, we were a couple living in Dublin with a two year old child. We had recently moved from San Francisco, where we were used to driving automatic and large cars. Daily life looked different now. Cold, wet weather was the norm. Mornings meant crèche drop offs. Weekends meant short trips to visit friends, and occasional longer visits from grandparents who needed space and easy access. A car was daily infrastructure.

That context shaped our criteria. We needed something easy to drive in traffic, simple to park, comfortable for a child seat, and practical for strollers, bags, and visitors.

P1: Non-negotiable

fail here, skip the car.

1 - Automatic transmission. Non-negotiable for our situation.

2 - Brand preferences.

Tier 1: Honda, Toyota, Volkswagen, Lexus
Tier 2: Hyundai, Nissan

I used reliability and repair-cost data (e.g. dependability scores, average repair cost) to rank. Premium brands (Audi, BMW, Mercedes) tended to need more frequent and costlier maintenance, so we excluded them.

If a car failed P1, we skipped it.

P2: Strong preference

Fail here, move on unless something else is exceptional.

3 - Number of doors. 4 or more (not 2).

4 - Car segment.

Tier 1: Saloon, SUV
Tier 2: Hatchback

If a car failed P2, we moved on unless something else was exceptional.

P3: Trade-offs

We could compromise if price and condition justified it.

5 - 2016 built or younger (5 years old, or younger, at purchase).

6 - Mileage. 15,000 km per year average; for a 5-year-old car that meant up to about 75,000 km total.

7 - Fuel type.

Tier 1: petrol, petrol hybrid
Tier 2: diesel, diesel hybrid
Not desired: electric-only at the time

8 - Single owner preferred.

9 - Carefully driven. No obvious signs of abuse or neglect.

10 - Features: all power windows, auto headlights, rear-view camera. Nice to have, not deal-breakers if the rest fit.

11 - Light colour preferred.

When viewing a car

We used a short checklist so we did not forget the basics. Check that all windows and the windscreen have the same matching number. If not, ask whether any were replaced and why. I started with a long checklist then realized that when buying from a dealer, I could skip many of those steps.

Before committing

We verified things we could not see on the lot.

Ownership transfer. Check whether the car was transferred in the last 3 months (e.g. in Ireland, motor tax / change-of-ownership records). The result will say either that no registration certificate was issued in the last 3 months, or that it was transferred to an individual on a given date. If the name on the logbook does not match the seller’s ID, ask how they acquired the car.
Car history. Run a history check (e.g. MotorCheck, Cartell, or your local equivalent). No news is good news.
Tax band. Confirm tax band and ongoing costs (e.g. motortax.ie or your local equivalent).
Insurance. Get a quote for that specific car; engine size and model affect premiums. Smaller engine usually means lower insurance. If we were not in a standard insurable category, we considered options like TheAA.
Age and mileage. We treated 5-7 years as a sweet spot for cost versus condition. If the car has a timing belt, check its replacement interval and keep some headroom (e.g. 30%). If no timing belt, we looked for under 100,000-150,000 km. For the same mileage, consider where it was driven (e.g. highway vs city start-stop).
Ongoing expenses. We budgeted for annual servicing, insurance, and any periodic tests (e.g. NCT; in Ireland around €55 per year). Roughly €400 per year for servicing was our optimistic baseline. Note: in Ireland a car will fail NCT once it is over 10 years old, so factor that into age and cost.
Depreciation (optional). To sanity-check value, we sometimes looked up depreciation for one model (e.g. one we were considering) across years. The comparison helped when deciding between similar options.

Sources

Dependability by make

Dependability score and average repair cost (€), high to low. Used to inform brand preferences in P1.

Honda: 93, €589
Toyota: 93, €651
Suzuki: 92, €466
Mitsubishi: 89, €916
Hyundai: 88, €635
Mazda: 88, €679
Nissan: 86, €573
Subaru: 85, €870
Ford: 85, €463
SEAT: 84, €523
Peugeot: 84, €447
Smart: 83, €429
MINI: 82, €547
Volkswagen: 82, €694
Fiat: 82, €459
Lexus: 82, €663
Renault: 81, €485
Vauxhall: 81, €514
Kia: 80, €574
Chevrolet: 79, €603

Takeaways

Write your priorities in order and group them into tiers. You do not need a long list. You need a clear order and a rule per tier: e.g. "fail P1, skip; fail P2, move on unless exceptional; P3 is trade-offs."
Separate must-haves from preferences. Our P1/P2/P3 split made it obvious when to skip, when to hesitate, and what we would compromise on.
Use the same list to explain your choice. When friends ask what you considered, share the list. When you look back, the tiers show why you said no to some options and yes to one.

For a template: take the P1/P2/P3 structure above, replace each line with your own criteria and order, then use it to filter and to explain your decision later.