Plan on changing the oil this weekend, I was considering Royal Purple, only hear good things about it. I know there isnt any oil that has some dramatic MPG / HP Increase, but what would you use on a 5.9L 4x4? 1998 / 37 Inch tires, if that matters any.

 

I use Mobil 1 10w30 and have had no problems and my dad runs royal purple in his excursion and loves it

 

Honestly? What ever you can afford/want/wish/like... When it comes down to it, Conventional is conventional. Then there syn blend, which I use. Valvoline Max life Syn Blend, 10w30. Then there's synthetic. Sunthetic is the best stuff ever. I love to use it when I can, but it's expensive.

how often do you change your oil? if you change it every 3000, conventional will work just fine. If you change it every 5000-6000 syn blend would be better. if you go 7000+, get some good quality synthetic. Mobil 1 is decent. Royal purple, IMO is th best stuff you can get, along with Amsoil.

And the filter can play a big part in oil changes too. Purolator is a good, less expenive filter. I would NEVER EVER buy a fram. ACDelco is another good one. along with Wix.

You have to think about how you drive your truck. Is it mostly city? Mostly Highway? Mixed? How long do you go between oil changes?

 

I would either go good conventional oil or pure synthetic, Semi synthetic is a rip off because there are no laws governing what the ratio of conventional to Synthetic is. Most of us think that its 50/50 but its not its more than likely 95% conventional 5% synthetic. This is no Bullsh*t i Actually heard thatfrom a Chevron Tech

 

I have over 100,000 miles on my 96 318 (5.2) and use Mobil one15W50 extended life and Mobil one filter. Change around every 10,000. I use the heavier oil because I figure with the mileage the clearances are a little more than they were when new.

 

I have only 57000 miles on my 360 (5.9), and I use 5w30 for the winter months, 10w30 for the summer months. It can get awful cold up here during the winter months. I did a lot of research when I first started changing my oil, and the common census online seems to be that Mobil 1 is the best synthetic oil. I haven't seen Royal Purple for sale up here, I'll have to take a second look around next time I buy oil.

As far as filters go, I've stumbled across a few sites where people have bought many different oil filters and dissected them to see which were best. The K&N and Mobil 1 filters seem to be the ones to get. I've heard Wix are good to, but haven't seen them reviewed. Definitely stay away from FRAMs, absolute junk.

I currently use K&N. For the 4.0L I6 found in Jeeps, the 5.2L, and the 5.9L, the model number is HP-2004.

 

i use mobil conventional with the lucas additive , and k$n filter mines has 123000 miles on it

 

I have been using Royal Purple in all 4 of our vehicles. On the Dodge I use a Pure One whatever the higher end Purolator filter is, on the Old Honda I used to use a K&N but decided to switch to a regular Purolator. Sometimes I will run regular oil in it as it has soo many miles I can't see spending $7 a quart when I can get oil for it that costs $2 although I only ran regular oil for a couple times then switched back to RP. I don't know what I will do next. On the Chevy I run AC Delco filters with Royal Purple. I used Mobil 1 Synthetic once when they were sold out of RP. In the new Honda I run Royal Purple with a Honda oil filter although this last time I Couldn't get a Honda one when I needed it so had to put a Pure One filter on it. I'm happy with it and like this combo the only downside is the cost. It's pretty expensive oil.

 

I use amsoil and amsoil filters. Can't go wrong the best...

 

I buy whatever conventional is on sale and i buy a napa filter(made by wix) and change it every 3000 miles. No problems and probably never will be