Just passing on my experience with an additive. I use Techcron, seems to do the job and has been recommended extensively. I also keep my 240 wagon well tuned and serviced regularly; however, many months ago, I had begun to develop an irregular idle and some occasional "clicking " sounds emanating from the injectors. Using Techron didn’t help. I went to my mechanic and was dreading perhaps a valve job, injector replacemnent, etc. He listened to the sounds, and instead of diving into a large possible "repair", suggested I first try Marvel Mystery Oil. I informed him I used Techron regularly. Now I have heard of and seen Marvel Mystery Oil (MMO) on the shelves of various places such as Kragens, for many years, never giving it much credence. Well, on my mechanics’ recommendation, I purchased a small bottle of it and following directions, put it in my gas tank. You can guess where this is leading. Yes, it worked!! The engine smoothed out within less than 2 tanks, and has never run better since I have owned my 240, for the last almost 5 years. Apparently my injectors were “sticking” and Techron just wouldn’t “unstick” them. I now use MMO about every 2-4 tanks, about 6 ounces at a time, and after quite a few months, the old engine is still doing very well!! I'm sold. Now, I do not use MMO in my oil although the directions say you can. I just don't feel any need to try it for that. Apparently, MMO works differently than Techron, adding vital lubrication qualities to the fuel, and no, there is NO smoke from it that I see coming from the exhaust, as I wondered there might be since it apparently is an "oil". I now buy it in the largest size I can, (for economics) and I fill my small bottle with it using a funnel. The reason for that is the small bottle is easier to use and it has measurements on the side so you can see how many ounces you are pouring in.

Here’s my disclaimer: LOL! No I do NOT have any “business interest” in MMO. I just like to pass on something that has worked well for me. I hope it might work well for someone else. Drive safely.