engine oil choice at over 200,000 miles?

Ok I have a new 2012 Tacoma, but I STILL have a 2000 Nissan Frontier. Pretend this is about a Tacoma if you like as it is a somewhat 'generic' question : )
The NF V6 has 216,000 miles on it and runs fine, passes emissions test. I have run synthetic oil in it until now [since buying it used w/42K miles on it].
Some oil has just started to drip slowly [a quarter size spot a week] out of the rear main seal. I think I've used 5w-30 AND 10w-30 depending on cold/hot weather at the time. It has had 10w-30 in it for the last 4K miles.
The NF will now 'sit' idle for days or weeks at a time since my Toyota is the truck I use every day now.
???Would you put petroleum based oil in the NF, or keep using synthetic? Would using petroleum based help stop/slow the oil drip?

What think?

 

dino won't stop the leak, but I would put dino in it if its going to be sitting a lot.

 

and BTW, the manual suggests either type {synthetic/petroleum} of oil as acceptable.

 

It does not matter. The whole point of running synthetic to to have extended oil change intervals. So like I said if you're only putting 5k per year on the truck go dino and change it every 6 months or so. If you put 20k a year on it use synthetic and change it every 5-7k miles.

 

Why change now? You're over 200k for fuck's sake.

The problem is the seal, not oil. If it's a slow leak and doesn't cost you more than an extra quart or two per month, I'd wait for it to get worse before I did anything. Just check your level regularly and keep up with scheduled changes.

Ah, no. Better mileage, better engine temperatures as well.

 

It's a minimal leak...and possibly has been going on for a while. I used to use the truck daily to the tune of 20K a year. Now that it sits for a week or more I 'notice' the quarter or half dollar size oil spot.
REchecked the manual, 5w-30 is the"preferred" oil, with 10w-30 and 10w-40 suggested IF the outside temp is 0 degrees F or higher. It almost never gets below 10 or 15 here in Geogia. With the 216K miles I thought 10w based oil might be best?..or would a 5w based 'still' be the preferred oil weight at this high milage point?

 

meh, just put some 5w-30 dino in it and run it. It'll be fine.

 

Why change now?....possibly [question] because the usage of the truck is now drastically different. Also wondered if dino squeezin's would be held better by seals....always heard synthetic tended to slip through seals easier than dino.

 

thats a popular myth that simply isn't true. 5w-30 is 5w-30 weather its dino or synthetic.

 

Theoretically a thicker viscosity may help piston ring sealing now that the engine has had time to wear and clearances aren't what they used to be.

On the other hand, thinner viscosity provides less drag and should allow less parasitic power loss.

The correct answer is:

This man is correct:

The VISCOSITY RATING defines a lubricant's VISCOSITY. For two lubricants to have different flow characteristics, they would have to have different viscosities.

Why this isn't immediately apparent to people I've never quite figured out.

Synthetics tend to cope better with heat and contaminants for longer. Hence why they are recommended for extended changes.

 

thanks for letting me slip in an 'outlaw' truck brand question in here guys!

 

...was because this 4x4 V6 NF has only 3 1/2 quart oil capacity! I figured they must not have designed the oil pan very well, or didn't have any room to make it larger. That's not very much oil doing a lot of work cooling/lubing!

 

If it's going to be sitting alot, especially outdoors, the additive package is probably the most important thing. Water forms due to the temp changes and can form acids in the oil, the additive package needs to take care of that.

"If it were me...", I'd stick with a synthetic with a good additive package (check BITOG for contenders) and still change the oil _at least_ once a year, more if you aren't running it for weeks at a time.

 

I ran Mobil One in a Dodge Dakota for about 15K miles with no problems. The rear main seal started to leak just enough to drip on the garage floor about like you describe your truck's leak. At the time, the truck was ten years old but only had 50K on it. I switched back to dino, no more leak. Sold the truck at 65K. The truck was 14 years old at that time and the only leak was a tiny bit of oil at the valve cover gaskets.

Dino isn't going to repair a worn seal, but my experience has convinced me that synthetic oil does tend to find the tiniest imperfection in a seal or gasket.

I'd try changing to dino and see what happens. It's not going to hurt anything.