Otto Explains — Choosing Features
Which Car Features Do You Actually Need?
Short Answer
Put proven safety features first: electronic stability control, automatic emergency braking, a full set of airbags and seat belt reminders, plus ISOFIX child-seat anchors if you carry children. Driver assistance features such as blind spot monitoring, a rear camera and adaptive cruise control are worth having when they match how you drive. Comfort and technology features are personal choices, and no feature replaces an attentive driver.
Which safety features have the strongest evidence?
Electronic stability control (ESC) helps stop a skid by braking individual wheels automatically, and IIHS studies in the United States found it reduces fatal single-vehicle crash risk by about half for cars and SUVs. Automatic emergency braking (AEB) brakes on its own when it detects something in the car's path: IIHS research found forward collision warning combined with automatic braking cuts rear-end crashes in half, and systems that recognise pedestrians cut pedestrian crashes by 27%. Airbags, seat belt reminders and belt pretensioners, which tighten the belt at the start of a crash, complete the core protection.
Which driver assistance features are worth paying for?
It depends on how you drive. Blind spot detection reduced lane-change crashes by 14% in IIHS research, useful on busy multi-lane roads. For parking and reversing, rear automatic braking showed the largest reductions in backing crashes of any rear system, and rear cameras became essentially required on new US cars from May 2018 because young children are often the victims of backover crashes. Adaptive cruise control keeps a set speed and distance on long motorway drives, but you still steer and must be ready to brake. Lane departure warning has a mixed record: it reduced some police-reported crashes but not insurance claims.
What can driver assistance systems not do?
None of today's assistance systems drives the car for you: the driver stays responsible and must stay engaged. Sensors may not work well in low light or bad weather, and lane systems can struggle where road markings are faded. A feature also only helps when it is switched on: in a 2023 study, lane departure warning was active in only 57% of the cars that had it. Choose systems you will actually keep on, and learn their limits from the owner's manual.
What should you look for if you carry children?
Look for ISOFIX anchors, a standard system for fitting child seats without using the seat belt. In the US version of the system, each equipped seat has two lower anchors and a top tether anchor, and top tethers greatly reduce how far a forward-facing child's head moves in a crash. Check how many seats have anchors, and whether your child seat fits the car before you buy.
How do you check that a car really has these features?
Equipment varies by version and market, so check the specification of the exact car, not the brochure for the range. Crash-test ratings help, but read them carefully: Euro NCAP tests a car with the safety equipment that is standard in the EU, and sometimes gives a second rating with an optional safety pack, so a car sold elsewhere may not match. For a used car, a pre-purchase inspection can confirm the condition of what is fitted, and a warning light such as an airbag light that stays on is a sign a safety system needs checking.
How should you choose comfort and technology features?
Think about the driving you actually do. Long summer drives make strong air conditioning and comfortable seats matter more; a city car may benefit most from parking aids. Screens, connectivity and premium audio add cost and are personal choices. A feature you would rarely use is rarely worth paying extra for.
Common Questions
- Is a five-star crash rating enough on its own? It is a useful starting point, but the rating applies to the car as tested. Euro NCAP tests cars with the equipment standard in the EU and sometimes rates an optional safety pack separately, so check that the car you are buying has the same equipment.
- Can I add features to a car later? Sometimes, but this article is about choosing at the time of purchase. Adding or activating features afterwards depends on the car and is a separate subject.
- Does adaptive cruise control drive the car for me? No. It keeps a set speed and distance from the vehicle ahead, but you still steer and must be ready to brake or accelerate at any moment.