synthetic or not,this is the ?

What's everyone running in their rides?I have a 351cj that's been rebuilt and then sat for 13yrs.she's up and running now but I'm not sure what to put in her.no pun intended.not sure how to break it in? Hit me with ur wise knowledge o keeper of the fords.

I intend to run synthetic in my 521 after it is broke in (maybe 10,000 miles or so?). I currently run mobil1 10w30.

What ilyes said is correct that

1. Let the engine break in
2. Old engines with aged/cracked/compromised seals have great potential to leak more with synthetic because the synthetic will do a better job at getting particles out of micro cracks in the seals and open up more potential leaks.

With that being said, I will assume that since the engine is rather old that it has been stored in a temperate environment out of the elements. If that assumption is correct, break it in and run synthetic later if you desire. Should be ok.

californiajohnny wrote: scott, isn't mobil 1 a synthetic oil?

Why,yes it is John. That was a great catch.

My apologies. I wrote what I *wanted* to be using, not what I am using.

I looked up my order history on Amazon (could have looked in my trunk also but the ipad was closer). It is Valvoline VR-1 10w30. The specific link to it on amazon is:

http://www.amazon.com/gp/product/B00DJ4FMK2/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1

There are other places to buy it of course.

Why VR-1? It has a high amount of zinc, ZDDP, which helps older engines. Comes in six packs. For the 521, that bastard takes like seven or eight quarts of oil so I had to get two packs. Good Dino-based oil for break in, or even every day use.

I mess with a lot of Jeeps, and the 4.0 engines LOVE the zinc. Synthetic fluids are wonderful, if your seals are new and in excellent shape, or on an engine that has seen regular activity and been running synthetic oil. I use synthetic fluids in every vehicle we drive (except Stripper)for the transfer cases, front/rear ends, chassis/steering components, engines. Transmission fluid is always dealer spec, as the more modern transmissions demand certain fluids.

On a break-in, I use Lucas ZDDP additive for the break-in, then change to full Synthetic fluids after that. Do not leave that in the crankcase for more than the break-in period. Ever.

Brands. I drive a tremendous amount of miles each year in gas-powered vehicles and have done quite a bit of research and experimentation with different Synthetics. All tests are done with Purolator filters (anti-drainback valves). Synthetics (tests done with my Titan, F-150, Dodge Ram, Civic, Acura TL, 4 speed GTS, Jeep XJ):

Castrol Edge Titanium - High quality oil. However, it does not cling to vital engine parts overnight or during non-use very well. Notice momentary clatter upon startup. Oil pressure drops dramatically when hot. 5W20, 5W30, 10W30 (viscosities I have used)

Pennzoil PurePlus - High quality oil. Better "clingability" than Castrol, less clatter upon startup, better oil pressure when hot. 5W20, 5W30, 10W30. (see above)

Valvoline SynPower - About the same experiences as Pennzoil. 5W20, 5W30 (see above)

Mobile 1 - High quality oil. More years of race/consumer testing, as it has been around far longer than the others (not basing any experiences on that). No clatter upon startup, better "clingability" than the others, FAR better oil pressure when hot, seems to clean better than the others. THE best oil on the market for my driving situations.

Royal Purple - High quality oil. EXPENSIVE as s**t. Used it in my Dodge Ram with the 4.7, did well, but no discernible difference over Mobile 1.

Now, I put my vehicles through more intense "tests" than 90% of drivers out there. Towing trailers/payloads of combined weight of 12,500 pounds from South Texas to Tennessee in 100+ heat non-stop (except for gas and food) with 1/2 ton trucks. Start/stop/start/stop, then hard charges on the highway, then more start/stop/start/stop - continuously for 2 week intervals. Traffic jams, road construction, idling for hours on pipeline ROW's in sweltering TX/LA humidity and heat. Winter driving in near 0 degree temps causing cold start after cold start with no real warmup. These kinds of tests.

No, I am not a professional "tester" of oils, but I have found what works the best for me in a variety of vehicles and conditions. I change my Synthetics every 5K to 7.5K miles. Yes, I know it is overkill, but my drivetrains are the difference between enjoyment/getting the job done and inconvenience/expense/missing deadlines/and sometimes death. When someone starts shooting at you on a pipeline ROW, you need to be able to mat the pedal, strain the drivetrain and get the f**k out of there...and be able to then drive 20 hours home with no worries. That is worth the added expense of additional fluid changes and superior fluids. Zero doubt.

Not meaning to rattle on, but these are my experiences with the different oils and reflect the worst-case scenarios.

Also, as a side note, if you do punish (not abuse) your vehicles, give them a regular pat on the dash, a good detail, sincere thank you's, and a set of Michelin tires. They appreciate that.

Laugh if you want, but...

Anyone do a taste test?

Wait, let me clarify that. I can taste the oil from the wisp of smoke from Stripper's tailpipe.

Funny you say that Joe, I worked on a 64 LTD last week. It is running a 302 and has leaky valve stem seals, let me tell you how wonderful it felt. That and the saggy bench seat, I went back 5 years and dove in the memories of my 73.