How To Estimate Repair Costs Before You Buy (And Save a Fortune)

Here’s the truth: estimating repair costs before you buy a used car is one of the smartest things you can do. Skip this step and you risk ending up with an expensive driveway ornament. Get it right, and you’ll save a fortune, avoid nasty surprises, and actually enjoy your new ride.

This guide breaks down exactly how to estimate repair costs like a pro - even if you’re not mechanically minded.

And before we dive in, remember: always run a full car history check before you buy. It reveals whether the car has been written off, clocked, or still has finance attached - all of which can massively affect your repair costs down the line.

Why Estimating Repair Costs Matters

You wouldn’t buy a house without a survey, so why risk buying a car blind? Repair costs can make or break the value of a used car.

• That cheap car might need £1,500 in repairs, making it more expensive than the better-looking car you ignored.

• That slightly pricier option might have had all the big jobs already done, saving you thousands later.

Knowing the potential repair bill upfront gives you leverage when negotiating and helps you budget realistically.

Step 1: Check the MOT History

One of the easiest and free ways to spot upcoming repairs is to check the car’s MOT history online.

Look out for:

• Advisories: Worn tyres, corroded brake pipes, suspension play

• Repeat issues: If the same advisory pops up year after year, it’s probably not been fixed

• Mileage consistency: Big jumps or gaps may signal trouble (or worse - clocking)

Pro tip: A car history check combines MOT data with other records to give you a clear picture.

Step 2: Research Common Issues for That Model

Every car has its weak spots. Some are known for turbo failures, others for electrical gremlins. A quick Google search like “common problems Ford Focus 2016 UK” can reveal the usual suspects.

Here are some UK favourites and their typical weak spots:

This step alone can save you from walking into a money pit.

Step 3: Estimate Repair Costs by Category

To keep things simple, let’s break repair costs into three main categories:

1. Wear-and-Tear Items

These are things that naturally wear out on every car.

2. Major Components

The scary stuff that makes buyers nervous.

3. Electrical and Tech Issues

Modern cars = more gadgets = more things to go wrong.

Step 4: Look at Age and Mileage

As a rule of thumb:

• 0–5 years old / under 50k miles: Mostly wear-and-tear items

• 5–10 years old / 50k–100k miles: Bigger jobs like clutch, suspension, timing belt likely

• 10+ years / 100k+ miles: Expect major repairs unless already done

A 10-year-old diesel with 120k miles is far more likely to need a new turbo or DPF than a 3-year-old petrol with 30k miles.

Step 5: Factor in Service History

This is where you separate the bargains from the disasters.

• Full service history: Many big jobs may already be done (timing belt, clutch, brakes)

• Partial history: Red flag - budget extra for catch-up maintenance

• No history: Walk away, unless it’s insanely cheap and you’re prepared for big bills

A vehicle history check confirms if the mileage is genuine and whether the car has been written off or had major repairs.

Step 6: Use Online Tools for Estimates

There are UK-based websites and garage networks where you can enter a reg and get average repair quotes. While not 100% accurate, they’ll give you a ballpark figure. Combine this with MOT history and common problems research for the clearest picture.

Step 7: Get a Pre-Purchase Inspection

This is the ultimate way to estimate repairs accurately. For around £150–£250, a mechanic can inspect the car and highlight what’s coming up. They’ll spot:

• Oil leaks

• Engine noises

• Gearbox problems

• Suspension knocks

• Warning lights

Yes, it costs money upfront - but it could save you thousands.

Real-World Example: Two Cars, Two Very Different Costs

The cheaper BMW actually ends up costing far more - a perfect example of why repair cost estimation matters.

Tips to Save a Fortune

1. Budget 10–20% of the car’s value for repairs - realistic for used cars

2. Don’t skip the inspection - it’s your best defence

3. Check MOT and service history closely - tells you what’s coming

4. Negotiate with knowledge - if tyres or brakes are due, use it to knock the price down

5. Run a car history check - avoid hidden damage and clocked cars

FAQs About Estimating Repair Costs

1. How much should I budget for used car repairs in the UK?
On average, budgeting 10–20% of the car’s value for repairs and maintenance is a good rule of thumb. For example, if you buy a £6,000 used car, expect to spend £600–£1,200 over the next couple of years.

2. What’s the most expensive car part to fix?
Gearboxes and engines are usually the costliest. A replacement gearbox can run between £1,500–£3,000, while engine rebuilds can climb even higher. That’s why checking service history and getting a pre-purchase inspection is so important.

3. Are electric cars cheaper to repair than petrol or diesel?
EV's have fewer moving parts, so they can be cheaper for routine maintenance (no oil changes, no exhaust issues). But when something big fails - like the battery - costs skyrocket. A replacement EV battery can cost anywhere from £5,000–£10,000, though most come with long warranties.

4. Is it worth paying for a pre-purchase inspection?
Absolutely. Spending £150–£250 on an inspection can save you thousands in hidden repair bills. It’s the cheapest insurance policy you’ll ever buy for a car.

5. Can a car history check really save me money on repairs?
Yes. A car history check reveals if a vehicle has been written off, clocked, or has outstanding finance. Buying a car with a dodgy past is one of the fastest ways to face huge repair bills - and in some cases, you might not even legally own the car.

Wrapping It Up: Repair Costs Don’t Have to Be a Mystery

Estimating repair costs before buying a used car might not sound as fun as picking the colour or trim - but it’s the difference between driving away happy and driving straight into debt.

By checking MOT history, researching common issues, breaking down costs by category, and investing in a pre-purchase inspection, you’ll know exactly what you’re getting into. Add in a vehicle history check, and you’re protected from the biggest financial traps.

The real secret? Smart buyers don’t just look at the asking price - they look at the true cost of ownership. That’s how you find a car that fits your budget and keeps you smiling long after you’ve bought it.