Not wanting to hijack someone elses thread, I'll start a new one. I have a 1990 Mercedes 208D with an Autotrail body. Very underpowered. From what I have read the 5th gear was all but useless. But a previous owner has installed a turbo and intercooler and it has helped no end. I can make it up most slight inclines in 5th gear, but a steep hill is still 3rd gear territory. (Or 2nd!!) I used a dose of RedX fuel system cleaner in my last tank. On todays run, and tankful later, it went most of the journey in 4th gear (I was on winding A roads, too slow for 5th) but I was amazed at how well it went, almost didn't have to change at all, just ran in 4th! More torque at low revs and happy on slight hills. I have checked the air filter and it is almost new. What else can I do to tweak performance? Bear in mind I am a total novice! Apart from the little things I can do for myself - with your guidance, of course - I was also thinking of this vortex exhaust system which jezport posted about. If it can add the slightest oomph I would think it money well spent. Do you think it will work? What other little jobs should I be doing to help bring some life back in to the old girl???