What Information Has the Biggest Impact on a Car Valuation?
When you value a car online, you’re asked for several details — but not all information affects a car valuation equally. Some factors have a much bigger impact on price than others.
This guide explains which details matter most in a car valuation, why they’re important, and how small differences can change the final figure.
The most important factors in a car valuation
While valuation tools use many data points, a few core factors tend to carry the most weight.
Mileage
Mileage is one of the strongest value drivers.
- Lower mileage usually increases value
- Higher mileage can reduce demand
- Mileage matters more on newer cars
Two identical cars of the same age can differ significantly in value based purely on mileage.
Age and registration year
Age affects value through depreciation.
- Newer cars typically retain higher value
- Older cars depreciate more slowly but still lose value over time
- Age and mileage are often assessed together
A low-mileage older car may still value well compared to a high-mileage newer one.
Vehicle condition
Condition plays a major role, even if it’s harder to measure automatically.
Valuation tools often assume:
- Average wear for age and mileage
But visible issues such as:
- Body damage
- Interior wear
- Warning lights
- Mechanical faults
can reduce real-world offers compared to an online estimate.
Factors that influence valuation slightly less
Service history
Service history helps confirm how a car has been maintained.
- Full or consistent history supports value
- Gaps may reduce buyer confidence
- Service history rarely adds value, but can protect it
It becomes more important on newer or higher-value vehicles.
MOT status
A long MOT can:
- Improve buyer confidence
- Reduce immediate costs for the next owner
An expired or failed MOT may lower value or limit buyer interest.
Specification and optional extras
Extras can influence value, but impact varies.
They matter more when:
- The car is premium or high demand
- Extras are widely desirable (navigation, automatic gearbox, upgraded trim)
They matter less on:
- Older cars
- Entry-level models
Why different tools prioritise information differently
Valuation providers weigh information differently depending on:
- Market demand data
- Buyer behaviour
- Risk tolerance
- Speed of sale assumptions
This is why entering the same details on different sites can still produce different results.
If you want a broader explanation of how values are calculated, our car valuation guidance breaks down the full process in more detail.
How to use this information when valuing your car
Understanding what matters most helps you:
- Enter details accurately
- Set realistic expectations
- Interpret valuation ranges properly
If you’re planning to value my car, focus on the information that has the biggest impact rather than chasing the highest estimate.
Key takeaway
Mileage, age, and condition have the biggest impact on a car’s valuation. Other factors like service history and specification support value but usually play a secondary role. Accurate information leads to more realistic pricing.
