For those of you who use it what do you think about it? Do you see or hear any difference?

Mobil 1 or Royal Purple... all the way. Never a single issue and valve train has been pretty much quiet for an OHV.

Snake oil for the car. If you change your oil regularly you don't need it. (or any other additive for that matter)

Use to be a rural mailcarrier and have used Lucas oil stabilzer for many years. In my use it was a big benefit for high mileage engines only. My route cars would start burning oil at around 160,000 miles. Usually would let out a huge blue cloud on start up. Tried STP with little help. My mechanic told me to try the Lucas product. Fact is it worked. Blue cloud was gone and cut the oil consumption in half. My mechanic said there is no reason to use it unless your engine is burning oil. Usually this only happens with high mileage. I sold both route cars and each one had over 220,000 miles on them. Both were Dodge Spirits with the 2.5L engine.

this is the thing. i have used it on older vehicles and it worked great. but i work at advance auto and people are telling me they are putting this shit in brand new cars and lucas is way to freaking thick in cars running 5w30 or 5w20. but then i thought stupidly, "am i missing something or are these people completely insane?" Here's one...a guy came in with a new mustang and bought a bottle of lucas and i told him, "I don't think your oil pump is going to like that stuff" and he insisted that it was great and this and that. so thats my take. I just wanted some feedback from you guys/gals.

You're right about the thickness of it. I think that the high viscosity is the only real benefit to using it. So if you have a high mileage vehicle and it's burning oil and that kind of stuff and you put in the Lucas it'll probably help. But so would just dumping a quart of 20w-50 or something higher. So like you said, it makes no sense to use it on new engines. It might even cause some harm. Either way, it's a waste of money but it makes people feel like they're doing something good for their car. Especially if they see good results. They just need to realize why the stuff works and quit wasting their money on it.

most of them have a seal expander in them. It can stop alot of leaks. I run purple in most of my cars but after so many miles shit starts to break.

The lucas has been know to "fix" seals. but other than that I don't think it does anything. too thick IMO

My mechanic said you don't need it newer engines. I guess if the guy with the Mustang wants to use it then thats his choice. My mechanic said it's made to a much different standard that STP. He said there not even close to being the same product and thats why people swear by it in high mileage engines. Like I said I never started using it until my cars had 160,000 miles on them and they were burning oil. Remember STP comes in a smaller size and the Lucas is a full quart. So your paying more but also getting more. If you read the directions it says you can use more than 1 qt. of the stuff if your engine is really using quite a bit of oil. I always bought my cars with less than 15,000 miles on them and always changed oil in the 3-5000 mile range and usually they started burning oil at the 160,000 mile mark. I can't complain about that.