I put Mobil 1 in my 1996 XJ with 160K on it. Runs like a champ and gets an average of 18-20 mpg.

 

yea im running mobil 1 clean 5000 i think its called....10w 30

 

I tried regular 30W rotella and a quart of lucas oil stabalizer this time around.........so far i dont think the jeep likes it..lifter chatter seems a bit high. Hope i didnt make a mistake with just straight 30W.

 

My jeep has over 260,000 miles on it,I use conventional oil with no problems.Any high mileage motor just use conventional oil,synthetic is so slick it will cause leaks on high mileage motors.

 

pretty damn good gas mileage. i've noticed that when i first started using Mobil 1, i did get better economy. i've tried other oils, from Castrol, Quaker State, Valvolin, and even Royal Purple, and i still think Mobil 1 is the best. i have some QS in it right now, but i'm going back to Mobil 1 at the next change.

 

I use 5W30 Valvoline conventional High millage. Runs super strong, dont intend on changing anytime soon.

 

if you ever seen the bearing test... you would go synthetic... but then yea if you have old seals and stuf.. thing will start leaking..

 

synthetic is better, BUT if you have used conventional all the life, then its not really a benefit, synthetic will hold up better at temperature, and under pressure and will not foam or boil.

BUT as stated above, synthetic has a lot of detergents and additives that can break down the buildup which in turn can cause leaks

Dont listen to the people who are saying that synthetic is thinner, the viscosity is the same for 10W30 conventional and 10W30 synthetic hence the 10W30, the difference is in the adhesion

 

rotella 10w30 and 1/4-1/2 qt lucas and a k&n filter went in mine on the last oil change my 94 with 130k loves it, no more knocks. I used to use qs and frams until I saw what fram filters look like when you cut em in half when they're spent. I had to have a buddy in the parts store order me the 10w30 rotella.

 

I've used Syntec in a 383 stroker Chev engine and it worked great however I realise not all engines are the same. I have a 93' XJ with 118Km's on it.

I'm currently using conventional Castrol 10w30 and thinking about trying synthetic which would you guys recommend Castrol Syntec or Royal purple?

Any info would be great.

Thank you
Mark

 

I use royal purple in my LT1 WS6, it adheres to surfaces and stays in the heads longer, way back when I was in college and worked at a Pepboys we had to go through this product knowledge training, and they showed Mobil 1 vs Royal Purple, it took 400 more psi to push the royal purple out of the bearing surface than mobil 1, so I switched from Mobil 1 to the Royal Purple, plus its purple and tastes like koolaid, just joking

 

^ Jonestown much? lol

 

recently switched to Valvoline max life syn Blend.....so far so good.

 

Apparently I am running Valvo High milage Mixed!!!! Eck. I didnt even pay attention last time.

Where do you all suggest i go from here I have got a busted Valve cover bolt and need a valve cover clean so going to have to clean and change soon anyway.

 

FYI there is a sale going on right now at Advance Auto, till 2-24, for 5 qts of M1 15K and a M1 filter for $30. Then they have a coupon in they're flyer for 5$ 0ff 25 or more, 10$ off $50, or 20$ off $100. I just got 4 oil changes, 20 qts of M1 15,000 and 4 oil filters for $110 w/tax. It had the breakdown on the receipt of the savings and I saved $90

My oil changing process goes like this. W/M1 15,000 10W30 run it for 5K change the filter, BTW I'm running the Ford 5.0 Filter holds an extra .5-1 qt, run it another 5+K and do the full change. My oil at 5K w/the old fiter looks like regular oil used to look in my old vehicles, w/dino oil, at 1000 mi.