Drivers being left confused by ‘garage speak’, says RAC

More than half of motorists say that they’ve struggled to understand the language used in garages to highlight faults with cars and the work required to fix them.

That’s according to research by RAC Breakdown, which surveyed 2,300 drivers to find out how they felt about certain terminology used in garages and service centres.

From terms like ‘big end’ (a part of an engine) to DFP (a filter which helps clean up exhaust emissions on diesels), drivers often have to navigate a minefield of different language to describe various components on a car and for many, it can prove confusing.

RAC Driver table
RAC Driver table

Some 50 per cent of respondents to the survey feel that they’ve been overcharged, while one-in-10 said that a garage had completed work that they hadn’t agreed to beforehand.

A quarter of drivers also felt that the final cost of repairs was far higher than they were initially quoted, while close to a fifth said that the garage wasn’t able to fix a fault for them at all.

As a result, the RAC has developed a new guide to ‘garage speak’ which can help explain some of the terms which are frequently used in a garage. Here’s a handful of some of the RAC’s explained terminology:


ADAS, which stands for Advanced Driver Assistance Systems. It can refer to many different safety systems on your car, from ones which prevent the vehicle from drifting out of a lane to others which can apply the brakes if they predict a collision.


An electrohydraulic brake system – or EHB – utilises an electric motor which is controlled by sensors in order to apply hydraulic pressure on brakes. It’s a common sight on hybrid and electric cars.

Excess play

No, excess play doesn’t mean you’re having too much fun – it’s a term used by mechanics to describe too much ‘give’ in a certain component. It’s often used in reference to steering; if you can turn the steering wheel without properly moving the front tyres, then this could be down to excess play.