In case you didn't know, they are made by TME in Sweden. TME don't say anything about linear/progressive on their site, but I'm sure JetDriver's reply is correct. (http://www.tme.se/e_main.htm -- but you won't find TME springs for the 240, as these are only made for IPD)

Here is TME's own hype:

"A TME Sport spring set is the best way to improve the suspension on your car. Developed by TME and manufactured in Sweden to ISO 9002 quality requirements, using the best quality Bekaert wire from Belgium.

The wire is made of chrome silicon in SAE 9254 or SAE 9260 quality. The springs are cold-wound on CNC spring coilers. After that, the springs are heat treated. If needed, the spring end(s) are then ground flat. Next step is shotpeening, which extends the life of the spring by more than 200 %. The next step in the process is to pre-set the springs. This is done by compressing the spring until the coils bottom out. This gives the spring a permanent set, so that it will not sag during its lifetime. The coating is done by a durable powder coat finish in black.

Each new spring is designed to evenly distribute the load and not to overload any section of the spring. The spring set will lower your car with approximately 15 to 50 mm, depending on application. The rates of the springs are carefully tested to give your car the best handling possible with very little sacrifice in ride comfort. Each spring set is covered by a limited 5 year warranty."

Erling.
--
1987 240 GL 82K miles