Techron D Concentrate Diesel Fuel System Cleaner, 20 fl. oz., 6 Pack

Great for my diesel pick up. Used it as soon as it arrived.

I'm sure the treatment is fine. My issue was that the package I received had (6) bottles, as expected. However, (2) of those were only ~ 62% full (by weight). All still looked factory sealed, but the two that were low were visibly "sucked in". There were no signs of leaking in the box . Weird. Anyways, Amazon was great and refunded my order. See pictures showing still-sealed bottles on my precision scale. One is normal; other is clearly missing a good bit of product.

The best fuel treatment going. I add an entire bottle every other tank full. Never an engine issue (3.0 Ecodiesel) in 75k miles.

Techron fuel system products are the real thing. When I worked for Toyota, this was the recommended product to keep your fuel system clean. Cleans injectors, cleans piston rings, cleans valves. I know, I worked on these engines. Just add it once a month, or even just once a quarter if you don't drive 12k / year.

I use this on my 2005 Duramax. It’s 20 years old and I just bought it with 87,000 miles. I used this prophylactically to prevent any would be injector issues. It seems to make the truck run quieter and give it slightly more pep. I like it. Seems like once every 3 or 4 months my truck makes a knocking sound. My research indicates it’s injectors knocking. When I put a whole bottle in a full tank of diesel it makes the sound go away.