Maintenance · do it yourself
How to check your engine oil, and what the dipstick tells you
Check it once a month, with the engine switched off and cold and the car on level ground. It takes under a minute.
Checks you can do yourself
Car care, used cars and electric cars
What you can check yourself, how often, and when it is time for a workshop.
Reviewed by Amara MusaMore about Amara Musa
Amara Musa is a light-vehicle technician, technical manager and periodic vehicle inspection controller, with over 20 years of hands-on workshop experience and experience running a workshop. Trained in Norway, with EV training and basic and advanced diagnostics training.
Last reviewed 13 September 2026.
Popular:
Quick answers
Most of these take a few minutes once a month, on a cold engine and level ground, and can catch a slow leak long before it becomes a bigger problem. Uneven tire wear is often the first visible clue of a steering or suspension issue.
Maintenance · check it yourself
How to check brake fluid, and when it needs changing
Once a month, with the engine off and the car on level ground, look at the brake fluid reservoir and read the level against its min and max markings.
Checks you can do yourself
Maintenance · check it yourself
When to replace brake pads and rotors, and what to look for
There is no fixed mileage. Pads and rotors are replaced by condition, because wear depends heavily on driving style, road conditions and climate, so they are inspected at every tire rotation or service.
Checks you can do yourself
Maintenance · do it yourself
How to check tire pressure, and how often to do it
Check all four tires, and the spare, once a month and before long trips, on cold tires before you set off.
Checks you can do yourself
Reading the tires
Uneven tire wear: what the pattern says about the car
Uneven or unusual tire wear is often the first visible clue of a steering or suspension issue.
Checks you can do yourself
Go through the car in order: the paperwork, a cold start, a walkaround in daylight, then a test drive at both low and highway speed. Any car you are seriously considering is worth a pre-purchase inspection from an independent mechanic.
Buying a used car
Used car paperwork: history report, title and service records
Get the VIN before you arrange to meet and run a vehicle history report. At the viewing, check that the name on the title matches the seller's ID, and that the VIN on the title matches the VIN on the dashboard and the door jamb sticker.
Buying a used car
Buying a used car
Used car cold start: why you should see the engine start cold
A cold start tells you more than a warm one. Several faults show themselves in the first minutes after a cold start and fade once the engine has warmed up, so a car that is already running when you arrive can hide them.
Buying a used car
Buying a used car
Used car inspection checklist: under the hood and underneath
Walk around the car in daylight before you get in for a test drive. Check panel gaps and paint texture, look under the car for rust, fresh undercoating and fluid drips, then open the hood and check the oil, coolant, battery terminals, belts and hoses.
Buying a used car
Buying a used car
Used car test drive checklist: what to check on the road
Start the car from cold if you can, then drive it at both low and highway speed. Listen for unusual noises while accelerating, braking and turning, feel for vibration or pulling to one side, and test the brakes firmly in a safe, controlled area.
Buying a used car
Winter range loss is mostly cabin heating drawn from the battery, not the cold itself, and anything involving the orange high-voltage cables is for a qualified technician only.
Electric car owners
Electric car maintenance: what it still needs, and what it skips
An electric car needs less routine maintenance than a petrol car, and less is the accurate word, not none.
Electric carsEV
Electric car owners
Charging an EV at home: the habits that help the battery
Home charging is AC charging: a wallbox or a domestic socket feeds the car's own onboard charger, which converts the power for the battery.
Electric carsEV
Electric car owners
EV fast charging: why it slows down, and what actually wears
DC rapid charging is normal, intended use. It slows down as the pack fills because the battery management system lowers the current to keep every cell below its voltage limit, and the last few percent wait for the weakest cells to balance.
Electric carsEV
Electric car owners
EV range in cold weather: why it drops, and what helps
An electric car loses range in winter mainly because the cabin heat has to come from the battery.
Electric carsEV
Buying a used EV
Used EV battery health: how to check it before you buy
On a used electric car, battery state of health matters more than mileage, age and equipment put together, and few sellers quote it.
Electric carsEV
A hybrid is not a car with less maintenance, and anything involving the orange high-voltage cables is for a qualified technician only.
A hybrid is not a car with less maintenance. Some items last longer, some are additional, and the petrol engine still needs everything a petrol engine needs.
Hybrid
Most manufacturers do not prescribe a valve cleaning interval, and a serviceable fuel filter follows the interval in the manual. Many in-tank modules have no routine interval.
Some direct injection engines build deposits on the back of the intake valves, because fuel no longer washes them.
Petrol
Amber · book a service
Weak fuel pump symptoms: misfires and power loss under load
A tired pump can hold pressure at idle and fall away when the engine asks for flow, so the typical sign is a misfire only under load.
Petrol
The preheat light is not a fault: wait for it to go out before you start. The particulate filter burns itself clean at steady speed, and AdBlue has to be topped up before the level reaches zero.
Amber · book a service
Glow plug light on a diesel: wait until it goes out
This light is preheating, not a fault. Wait until it goes out before you start. If it flashes after the engine has started, that is a fault.
DieselWarning light
Amber · book a service
DPF light on: drive, do not park
The filter needs to burn itself clean, and it can only do that at speed. Take a longer drive at a steady pace instead of parking the car.
DieselWarning light
Amber · book a service
AdBlue warning light: fill up before it reaches zero
Top the AdBlue up before the level reaches zero. If the tank runs completely dry, many cars refuse to restart, and by then topping up at the roadside does not help.
DieselWarning light
Car care guides for hydrogen cars.
Coming soon
Guides for this type of car are on the way and will appear here.
No guides match. Try another word, or .