Use it in my 1980 924. Older car no computer as with new cars. Worked great. A noticeable difference. A newer car's computer will make adjustments to the mixture so no immediate effects will be noticed. Over time deposits should be removed. Continued use is the secrete. Every few tanks add a bottle. This is my opinion based on performance, What needs to be done is a before and after look at the piston for deposits with an arthroscope. To late for me as I can not provide a "before" as I use it religiously. read full review »