Kia Optima (2018)

Estimated running costs and MOT pass rates from 4,827 MOT tests in 2024.

Annual Cost

£1,824

£152/month

MOT Pass Rate

88%

Good

Road Tax

£200

Standard rate/year

Est. Insurance

Grp 12-25

1598cc Diesel

Solid Option

88% pass rate, £1,824/year to run. 6 points above average.

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Diesel1598cc8 years old4,827 tests71k miles avg

Annual Running Costs

Fuel (Diesel, 1598cc)

~55 mpg

£1,219

Road Tax

Standard rate (from April 2017)

£200

MOT Test

£55

Predicted Repairs

£350

Total per year£1,824

Per month£152/mo

Per week£35/wk

Estimates based on 7,400 miles/year (UK average), diesel at 199.33p a litre (GOV.UK weekly average, week of 19 October 2026), GOV.UK road tax rates and repair likelihood from MOT data. Insurance not included. Cars registered from April 2017 pay the £200 standard rate, plus £440 a year for five years (from the second year) if they cost over £40,000 new (over £50,000 for electric cars).

Reliability Verdict

88% MOT pass rate(Good)

0%All-model avg: 82%100%

Good reliability. Occasional issues but generally solid. That's 6 points above the average of 82% across all models in our data.

88% of MOT tests on Kia Optimas from 2018 ended in a pass in 2024, when they were about 6 years old. That's based on 4,827 tests across the UK, retests included. The average mileage recorded at those tests was 70,738 miles.

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How Does It Compare?

Rank among 2018 models409th of 607(bottom half)

Rank among Kia models287th of 471(bottom half)

vs average of all models+6%(82% avg)

vs 2018 models average-1%(89% avg)

vs Kia average+2%(86% avg)

Mileage Analysis

70,738

Average miles

44,400

Expected for age

The average 2018 Kia Optima had 70,738 miles on the clock at its 2024 MOT, which is well above the expected 44,400 miles for a 6-year-old car. Check service history carefully, as high-mileage cars need consistent maintenance to stay reliable.

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Best Year to Buy?

Of the years with at least 100 tests, the 2020 model has the highest MOT pass rate at 91%, while the 2012 model has the lowest at 74%. The 2018 scores 88%. Newer cars usually pass more often simply because they are younger, so compare years of a similar age.

Kia Optima by Year

Year	Pass Rate	Tests	Avg Mileage
2020	91%	241	57,554 mi
2019	89%	3,111	60,554 mi
2018	88%	4,827	70,738 mi
2017	87%	5,853	79,204 mi
2016	87%	2,187	78,458 mi
2015	84%	1,258	81,466 mi
2014	78%	1,178	91,247 mi
2013	80%	618	99,105 mi
2012	74%	1,452	100,410 mi
2011	76%	51	105,766 mi

Similar Cars to Consider

Volkswagen Golf

2017 · 1598cc Diesel

£1,674/year

91%

+3%

Ford Focus

2019 · 1499cc Diesel

£1,824/year

89%

+1%

Mercedes A

2019 · 1461cc Diesel

£1,674/year

91%

+3%

Mercedes A-Class

2017 · 1461cc Diesel

£1,824/year

88%

same

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About the 2018 Kia Optima

The 2018 Kia Optima is a small family car. Our records list a 1598cc diesel engine, though engines vary between versions. 4,827 MOT tests were recorded on this model in 2024, making it a reasonably common sight on UK roads. Among all models from 2018, the average MOT pass rate is 89%, and this model falls short of that benchmark.

With an average of 70,738 miles recorded at its 2024 MOT tests, Kia Optima owners cover more miles than the average driver. High-mileage examples should be checked carefully for wear on suspension, brakes, and drivetrain components.

2018 Kia Optima Fuel Costs

The 1598cc diesel engine offers a reasonable balance between performance and economy. Expect around 55 mpg in mixed driving, which works out to roughly £1,219 per year with diesel at 199.33p per litre (GOV.UK weekly average, week of 19 October 2026; based on 7,400 miles per year). Diesel cars of this age should have their DPF (diesel particulate filter) checked, as replacements can be costly.

What does it cost to own a 2018 Kia Optima?

Total estimated annual running cost is £1,824 (£152/month), broken down as £1,219 fuel, £200 road tax, £55 MOT, and £350 predicted repairs. Repair costs are moderate, reflecting the 88% pass rate. Keeping on top of servicing will help avoid surprises.

Kia Optima Reliability Trend

Newer Kia Optimas pass their MOT more often than older ones, by 9 percentage points on average, which is mostly down to age and wear.

Buying a Used 2018 Kia Optima

At 8 years old, this is a solid used buy if you find one with good service history. Depreciation has levelled off, so you won't lose much more value. Focus on condition over mileage. If you're flexible on year, the 2020 model has the highest pass rate at 91%.

Common Issues to Watch For

These are typical issues for cars of this age, fuel type and engine size, not faults recorded on this model's MOT tests. Use them as a checklist when you view one.

DPF (Diesel Particulate Filter)

Watch out

Short journeys clog the DPF. Replacement costs £1,000-£2,500. Check the DPF warning light and ask about driving patterns.

Turbo Wear

Watch out

Diesel turbos work harder and wear faster. Listen for whining noises and check for oil leaks around the turbo housing.

AdBlue System

Medium risk

Post-2015 diesels use AdBlue for emissions. Sensor failures and tank heater issues are common. Budget £200-£500 for repairs.

EGR Valve

Watch out

Exhaust Gas Recirculation valves clog with carbon deposits, causing rough running and poor economy. Cleaning costs £150-£300, replacement £300-£600.

Suspension Wear

Medium risk

Shock absorbers, springs, and anti-roll bar links typically need attention around this age. Listen for clunks over bumps and check for uneven tyre wear.

Service History

Low risk

Always request a full service history. Regular servicing is the single best indicator of how well a car has been maintained, regardless of mileage.

Running Costs Compared

How the 2018 Kia Optima stacks up against similar cars for estimated annual running costs, insurance group, and tax.

Car	Pass Rate	Fuel/yr	Tax/yr	Est. Ins. Group	Total/yr
Kia Optima(2018)	88%	£1,219	£200	Grp 12-25	£1,824
Volkswagen Golf(2017)	91%	£1,219	£200	Grp 12-25	£1,674-£150
Ford Focus(2019)	89%	£1,219	£200	Grp 12-25	£1,824same
Mercedes A(2019)	91%	£1,219	£200	Grp 12-25	£1,674-£150
Mercedes A-Class(2017)	88%	£1,219	£200	Grp 12-25	£1,824same

Estimates based on 7,400 miles/year, GOV.UK average pump prices for the week of 19 October 2026, GOV.UK road tax rates and MOT data. Insurance groups are our rough estimate from engine size, not official groups. Actual costs vary by driver, location, and usage.

Questions about the 2018 Kia Optima

Is the 2018 Kia Optima reliable?

Good reliability. Occasional issues but generally solid. 88% of MOT tests on 2018 Kia Optimas ended in a pass, from 4,827 tests (DVSA MOT data for tests in 2024, retests included). That's 6 points above the average of 82% across all models in the same data.

How much does a 2018 Kia Optima cost to run?

Our estimate is £1,824 a year (£152 a month): £1,219 fuel, £200 road tax, £55 MOT and £350 predicted repairs, based on 7,400 miles a year. Insurance is not included.

What is the MOT pass rate for a 2018 Kia Optima?

88% of 4,827 MOT tests on the 2018 Kia Optima ended in a pass (DVSA MOT data for tests in 2024, retests included). That ranks it 409th of 607 models first registered in 2018 (bottom half).

Which year Kia Optima has the best MOT pass rate?

Of the years with at least 100 tests, the 2020 Kia Optima has the highest MOT pass rate at 91% and the 2012 the lowest at 74%. Newer cars usually pass more often simply because they are younger and have done fewer miles.

What is the average mileage for a 2018 Kia Optima?

The average mileage recorded at MOT tests on the 2018 Kia Optima is 70,738 miles, which is well above the expected 44,400 miles for a 6-year-old car. Check service history carefully, as high-mileage cars need consistent maintenance to stay reliable.