[clidefr0g]

from 99-04 ford recommended 5w20 and 5w30 for different months of the same year manufactured vehicles and they all have the same engine. you would never have a problem running either of them, but as stated 30 gives more protection and 20 gives more mileage.

And you are correct the manufacturer does recommend things for a reason, that reason; however, is what makes them the most money while still providing a decent product. And if they can advertise a higher MPG than something else, that will make them more money.

[Codeman]

OK well I asked my teacher today on the tranny fluid. He said all they did was add 1 quart of automatic transmission fluid to the oil. They then took the car out and got on it as he said. And a lot of times that would clean the varnish off the lifters. HE said you will want to change your oil after you do this.

[Rich J]

So I take it you did it after you spoke with him right? I want to see your results before I do this

[Codeman]

I did not do it after I spoke with him. Sorry man, I have around 1k left till my next oil change so it will probably be a couple weeks. Sorry man. I will let you know once I do it though.

[9986paulk]

New cars alspo recommend waiting at least 5k to change oil too. I do it 3k regardless. Sometimes I think they recommend stuff so your engine actually wears out a little faster. But as far as the weight goes, I'd run 5-30 in all of the 3.8s. There's no reason to change it with no real mechanical differences.

And btw, has anyone ever tried to test for a difference in gas mileage with te 5-20 to 5-30? I doubt you'd be abe to tell any legitimate difference

[Codeman]

I doubt there is any difference. I am not at all concerened about running 5 20 in my car. Have been for three years.

[CRA 8]

run 5w-30 royal purple

[Codeman]

I will never run synthetic, too expensive and a waste of money.

[stephen]

If it's actually a lifter problem 1qt of ATF with the oil may help.

It could also be a worn rocker arm and the ATF won't help that.

[Codeman]

That is another possibility. I almost thought it could even be a broken valve spring. My car feels like it is missing. I am not sure if it is because I can't get my final tune yet? Or what?

I guess I will try the ATF first and hopefully that fixes the problem. If not then I will have to pull both valve covers off and take a look. Well if a valve spring is broke, then it gives me an excuse to get a new cam quicker . Because if I have to put a new valve spring in might as well replace them all and throw in a cam

[adryan]

Did you ever get the ATF to work on your sticky lifters? Please update... I think I got the same issue.

Thanks.

Adryan

[1slowv6]

Originally Posted by Codeman I will never run synthetic, too expensive and a waste of money.

its not a waste of money, it has a conventional base but much better detergents in it for cleaning your engine and keeping it lubricated longer. ive gone 10k on synthetic before without problems.

i also replace my plugs every oil change.

[Jetflo]

If you are going for snake oil, I'd do the marvel mystery oil over tranny fluid. It is probably just mineral oil, but it has in past experience done some good for noisy valve parts.

You can use Seafoam to flush the crankcase beforehand, but it really works best in the intake. While you are trying out various oil treatments, it is probably fine to run dinosaur oil.

You'll want to change it within a week or two after any snake oil actually works. There's a reason we don't use a cocktail of additives at every oil change.

Still using Royal Purple 10W30 at 130K miles. It is an early 2001 V6 Mustang. It runs just fine. I remember Ford introducing the 5W oil to get 0.25 MPG fleet average. It was never necessary to use 5W oil unless you live where it gets pretty cold.

It does not get cold here.