Amsoil has something to sell, Dr. Haas doesn't. With the big filter (FL-1A), 6 qts. of oil puts the oil level spot on the max mark on the dip stick.

As the good Dr. says, the 1st number is more important than the second and the lower/lowest 1st number is always best.

How old are those articles about zinc and flat tappet cams......other than very old and probably false but perpetuated on the Internet.

 

Well i may go with amsoil 0w-30. I dont know, what synthetics do yall recommend?

 

you will only want to go synthetic IF you have ZERO leaks.

If you have a leak the synthetic will make it that much worse....

 

Yeah i know, i've had zero leaks with this XJ and might as well give synthetic a try. always trying something new. I'm going to change the oil pan gasket when i change the oil

 

I am not really crazy about the Signature Series oils. Yes, they are still very good oils. But for the 4.0l application there are better choices.

How about the Series 3000 Heavy Duty Diesel oil? Its a 5w-30 and has 1378 ppm of Zinc and 1266ppm of Phosphorous.

 

i run a pureone oil filter came highly recomended

 

Does it say it on the bottle that it has that much zinc?

 

All i'm looking for is a synthetic that has alot of zinc in it

 

Zinc levels in all oils are lower today.......zinc is a pollutant and bad for cats.

 

What I can't brush my cat with a galvanized hair brush?

 

Yep, the stock filter youd put on a Ford 300, you can use on 93 and newer 4.0 motors. Napa Gold 1515 or ProSelect 51515 for only $3.49 reg price are the ones I use. Hold an extra 1/2 quart! I dont know about that 0w-20 syn oil recomendation either. Im gonna do a Castrol Syntec 0w-30 oil change on 2001 tomorrow. Thats as low as id go, unless your in constant 0degree weather. Ill let you know how this 0w-30 change goes. The 4.0 really needs a 30 weight oil. This grade of Syntec is supposedly the only Group 4 base oil Syntec, meaning its a true synthetic. As long as it says made in Germany on the back of bottle. HIGHLY regarded on many high performance car forums, so im tryin it in my beloved XJs now. Gonna start with ones that have minimal oil seepage, cause a group 4 or group 5 base oil will seep to leak.

 

Oh and this Castrol Syntec 0w-30 has higher levels of Zinc than any other Syntec. Its still rated as an API SL, and dosent have the Starburst symbol on front of bottle. Its European, and they all use higher levels of zinc in their 160 mph vehicles. The main oils here in the U.S. you have to worry about having lowered levels of zinc and phosphorus are the fuel economy grades, which have the starburst symbol on front. Those grades are the 0w-20, 0w-30, 5w-20, 5w-30, 10w-30. And there are many brands that are those weights, but arent API certified. You can tell, on those grades, if the starburst isnt there. Like Royal Purple. All of their oils are API SL rated, which ended in 2004 because of federally mandated lowering of zinc and phosperous levels to extend the life of cats. MOBIL 1 HIGH MILEAGE 5w-30, 10w-30(proab best), 10w-40, my main recomendation.

 

All the Amsoil products are great. I have a stash with pretty much 2 of everything they sell worth $10,000+. ALL of REDLINEs products are excellent. Royal Purple has very, very good oils also. Very good break-in oil, Royal Purple has in perfect 4.0 liter 10w-30 weight. If it was my main recommendation for any Jeep 4.0, it would be Wal-Mart bought, 5 quart $21.00 jug, Mobil 1 HIGH MILEAGE 5w-30, 10w-30, or 10w-40. Do it. Just that. Its #1. Itll go for long time.

 

So would the amsoil 3000 series have more zinc than the castrol syntec 0w-30?

 

NAPA gold 1085 is the regular filter. NAPA gold 1515 is the oversize filter. You do not have to put the extra oil in the oversize filter if you do not want to. it just gives you the option. WIC filters are used by NAPA.