A tougher set of MOT test rules will be introduced on 20 May, making it harder for your car to get through the annual roadworthiness check. We’ll detail what those changes are below, but if you need to get up to speed on what the MOT is and how it works, our previous blog on the MOT system will reveal all – our article on how to decipher your car’s MOT history is also worth a read.

All cars need regular maintenance, but modern vehicles are so good at taking neglect that we’ve become very lazy when it comes to ensuring our cars are in good condition. Our roads are full of cars driving around on bald or under-inflated tyres, with worn-out suspension and with brakes that are in dire need of an overhaul – the MOT is in place to keep this to a minimum.
The Road Traffic Act says it’s a criminal offence to drive a vehicle in a dangerous condition, yet British drivers still aren’t very good at maintaining their cars. It’s a good job we have the MOT, because even drivers who do get their cars regularly serviced are often surprised by the faults that are picked up during the annual test – items such as chafing brake hoses, worn shock absorbers or tyres that have sustained damage on the inner sidewall, out of sight.
When the new MOT rules kick in later this spring, all of these checks will still be made, along with some new ones in a bid to raise the bar even further in terms of maintaining vehicle standards. All cars will find it harder to pass, but diesels in particular will be targeted, in an attempt to ensure that they’re as clean as possible.
The biggest change with the new MOT is the introduction of three new fault categories: minor, major and dangerous. The first of these takes the place of the advisories that have been issued for several years. These are the small problems that could become big ones if you don’t keep an eye on them, such as tyres getting close to the legal limit. If it’s already a big problem it’ll be marked down as a major fault, which means the car fails its MOT.
Beyond this there’s a third category which in theory would only become an issue on a car that’s been neglected: the dangerous fault. This would be something that requires immediate attention, and just by driving the car away from the test station you would almost certainly be committing a criminal offence, as you’d be driving a car that you know is not in a roadworthy condition.
In a bid to improve air quality, newer diesel cars are coming in for particular scrutiny. Since 2009 it’s been mandatory for all diesel-engined cars to be fitted with a diesel particulate filter (DPF). These massively reduce the amount of soot that’s emitted from an exhaust but DPFs can also get clogged up and fail; they also slightly reduce power and increase fuel consumption.
As a result, many owners of cars that cover only a low annual mileage have had all sorts of problems with their diesel-engined vehicles, with some resorting to having their DPF removed. Unsurprisingly, removing a DPF is an offence which is why from 20 May, MOT testers will be looking for signs of the DPF having been tampered with, or removed altogether.
These post-2009 cars are the ones that will have the toughest time, because if they emit “visible smoke of any colour” they will fail the test, as the smoke will be deemed a major fault. Before you start panicking, just remember that the whole point of a DPF is to stop your car’s exhaust from emitting any smoke, so if there is smoke present the car needs to be fixed.
One key change that was proposed but which didn’t make the grade was to have a car’s first MOT when it reaches four years old instead of the current three years. The government claimed that by putting off the first test by an extra year, drivers would save around £100m annually – but the risk of extra crashes caused by poorly maintained cars was just too great. According to government figures, one in six cars fails its first MOT because of insufficient maintenance, which means that had the change to four years come in, 385,000 unroadworthy cars would be driving around for a year before those faults were picked up.
Despite this, the government has decided that cars that are not modified and which are 40 years old or more, are no longer subject to an annual MOT inspection. This doesn’t prevent owners of such cars presenting their car for an MOT anyway, but from 20 May there will be no compulsion to do so, which is quite worrying. That’s a rolling 40-year exemption by the way, and from 20 May it’s estimated that 490,000 classic cars will be MOT-exempt, which is about 2% of the cars on UK roads.
The new rules are intended to reduce the chances of unsafe and heavily polluting cars being driven on our roads and there’s nothing to be afraid of. As long as your car is serviced according to the manufacturer’s schedule and new parts are fitted when needed, your car should sail through the MOT.
Richard Dredge
February 2018
Use our free MOT History check which will show you the full MOT history of a car. You can also opt in for free MOT and road tax renewal reminders.