Originally Posted by sxrfun

75w /140 is more expensive if i remember correctly.....only reason you need it in the rear is for greater protection while heavy towing ...do you ever haul heavy for long trips in 4 wheel drive?

Originally Posted by 351Cleveland C4

I see it the other way. Lucas has been proven time after time in many different high-performance and racing applications.

Originally Posted by 351Cleveland C4

Lucas oil has been there and performed...

Originally Posted by F357

Once again, proven how?


There is NO evidence that it performed any better than the cheapest store brand product. It HAS been proven that several of their products are snake oil. That means they aren't going to put any extra effort into their gear oil either. It only says they think their customers are too ignorant to know the difference.

Originally Posted by askoop

So your vote is for the Valvoline synpower?

Originally Posted by askoop

OK, ford recommends 75w90 for the front diff, but would there be any draw back to running 75w140 in the front as well as the rear?

Originally Posted by hodge5

You made the statement that Lucas is snake oil. Not all of their products are, especially synthetic or semi-synthetic gear oil. I have nothing to prove to you, and just because you said that Lucas makes questionable products doesn't make it so. I don't have to get oil tested to know whether it is performing or not. People have judged that long before there was oil analysis. I've never had oil analyzed, nor have I had reason to or problems from not getting it tested. The original question was about Valvoline versus Lucas, and I have been running Lucas with no problems. So, that may not satisfy you, but hopefully it will satisfy the original poster.

Originally Posted by Tennesseepowerstroke

Good answer. Check his previous fights, err posts. Where is the popcorn smiley when you need it?

Originally Posted by F357

It will work alright but will reduce fuel mileage a tiny bit.

Originally Posted by 351Cleveland C4

You're splitting hairs on a subject that doesn't need hairsplitting. I would put money on the cheap store-brand oil doing the same job as the comparable top dollar stuff, and nobody being able to tell a difference in real life.

Originally Posted by F357

There is nothing wrong with asking for an explanation when somebody thinks an oil is any good. Most cannot ever give a reason. It's usually because they like the bottle it comes in. An answer like "it still looks clean" is ridiculous.

Lucas produces a good product as well as many other manufacturers. Doesn't matter what his explanation is.

The absolute fact is most people do not know how well their differential fluid is performing or not. The best they can say is it still spins. Very few people have a gauge or ever do an analysis. You can't tell by popping your finger in the hole.

Originally Posted by Tennesseepowerstroke

I have stuck my fingers in many holes and can get a good idea if anything is wrong, not always, but most of the time.