i have been speaking to a few people and researched tetraclean in the fuel line, injectors from speaking to a mechanic friend he says that he has got an extra 70 miles per tank and a increase in power on a bmw 3 series diesel i have seen on other car forums that they say the same i have only found that a couple of peoples injectors have failed after the treatment, what im asking is has anyone on here used tetraclean and have they noticed any improvment. I am thinking of doing this on a 2007 2.7 diesel with 168k on the clock many thanks in advance