Before this gets out of hand with opinions, I suggest you visit bobistheoilguy.com and have a look around.

@T4R2014 was right. You don't even know if you have a sludge issue.

In the end, these trucks are capable of reaching high mileage with any quality oil and filter. The key is changing it on time.

Coming from Audi/VW, the 96-05 1.8T engines were well known for their sludge because of owners running conventional oil for 5K internals.

My Audi was pretty well maintained but yet had sludge at 105K. Forum members suggested AutoRX https://www.auto-rx.com/

Adding a bottle in your oil change, its a slow cycle over 3000 miles. After my 2nd cycle, pulled the valve covers and they looked amazing. For about $30 shipped, its a great option for basic or deep cleaning.

Youre saying that was in your Audi or T4R?

seafoam is a solvent which IMO should never be used in the engine oil it is not a lubricant . also using solvents will loosen up the sludge created by conventional oil too quickly causes damage to the engine restricting passageways and gets into the piston rings etc...

since I do keep my vehicles for a couple of decades with high miles the use of marvel mystery oil of the proper amount removes sludge and the carbon deposits. it is a oil with high amounts of detergents.

I use 5 OZ of the MMO in the engine oil 300-500 miles prior to the oil change . this then removes most of the sludge but not all. then after the oil servicing add 5 OZ MMO again and run it until the oil begins to get dark . then do another oil change. that should take care of it .

having used synthetic mobil 1 engine oil dexos spec. I have found no sludge issues . PCV looks very clean. I do a 7500 mile oil changes .

I also use MMO in the gasoline . 1 OZ per 10 gallons of gas. this cleans and lubes the fuel delivery system keeps the fuel pump in good condition as well as the injectors.

obviously some think more is better well that is not proper !

Walmart has it for $4.50 QT. MMO been around for over 50 years. used for many other uses .

diesel owners use this product all the time.