The motor insurance industry is warning carmakers against the use of the word "autonomous" in their marketing.
A report for the Association of British Insurers says the way some advanced vehicles are described can convince motorists that they have self-driving cars when that is not the case.
There are no fully autonomous cars on British roads.
However, manufacturers such as Tesla, BMW and Nissan offer features that can partially automate the driving process.
These include systems that keep the car within its lane, control its speed and keep it at a safe distance from the vehicle in front.
Thatcham Research, which conducts safety tests for the motor insurers, says the manufacturers need to be far clearer about the difference between these assisted-driving systems and autonomous cars.
The organisation says misleading names such as "Autopilot" and "ProPilot" give drivers the impression their cars can drive themselves in all circumstances.
"There's a problem with the manufacturers trying to introduce technology and consumers not being ready for it, not being sure if it's automated or 'Do I need to keep watching?'" says Matthew Avery, of Thatcham Research.
"We want it very clear. Either you are driving - assisted - or you're not driving - automated."
To demonstrate the dangers of partial automation, Thatcham took a Tesla out on its test track at Upper Heyford, in Oxfordshire.
With the Autopilot system switched on, the Model S kept in lane and slowed to a halt when a car it was following encountered standing traffic.
But on a second run the car in front switched lanes at the last moment, and the Tesla was unable to brake in time, running into a stationary vehicle.
"This is an example of what happens when the driver is over-reliant on the system," says Matthew Avery.
In April, a British driver lost his licence after being filmed on the motorway sitting in the passenger seat of his Tesla using its Autopilot system.
A Tesla spokeswoman said: "When using Autopilot, drivers are continuously reminded of their responsibility to keep their hands on the wheel and maintain control of the vehicle at all times.
"Tesla has always been clear that Autopilot doesn't make the car impervious to all accidents and the issues described by Thatcham won't be a problem for drivers using Autopilot correctly."
Thatcham Research, which works for the Association of British Insurers, is launching a testing programme to assess assisted-driving systems.
"Manufacturers must be responsible in how they describe and name what their vehicles can do, and the insurance industry is ready to hold them to account on this," said James Dalton, from the ABI.
The insurers are are also concerned about manufacturers' plans to introduce cars with level-three automation, where the driver can take their hands off the wheel for long periods.
They would like the carmakers to skip this step and wait until they are ready to go straight to level four, where the vehicle is fully automated.
In response, Mike Hawes, chief executive of the society of Motor Manufacturers and Traders said: Fully self-driving cars are still a long way off, but industry is working now with regulators in the UK and at UNECE (United Nations Economic Commission for Europe) level to determine what makes a vehicle fully autonomous.
"This will ensure there is a common understanding and that all autonomous cars meet exacting international standards."