pls advise: conventional or synthetic

[noobshooter]

I use Mobil 1 5w/30 every 5000 miles.

btw...I noticed you are also in Houston. Usually Walmart or Auto Zone has the best price on Mobil 1.

 

[MikeInNH]

Use whatever oil that meets your cars requirement. Synthetic has PROVEN to be a superior oil...the question comes in does it make much of a difference for auto's. In MOST cases..the answer is no.

Where synthetic oil is useful is...in extremely cold (below 0)...towing (which many of us do).

I've NEVER found a brand name oil that doesn't meet ALL manufacturers specs. So I'm not sure one oil is going to really make much of a difference over another. I've been using either Mobil-1 or Gastrol Syntec for the past 15 years.

My 90 Pathfinder I used nothing but conventional oil. I sold it with about 310k miles on it. It started to burn a little oil at about 250k miles. My 98 Pathfinder I started using synthetic by it's second year. I gave it to my daughter for college when it had about 340k miles. At the time it wasn't burning any oil. She sold it to her ex boyfriend a few years alter when it had over 450k miles. Last I knew it was approaching 500k miles. My current 4runner has over 240k miles and it's not burning any oil.

As for extended oil changes...No manufacturer I know of says you can extend the oil change interval if you use synthetic oil. In fact if your vehicle is under warranty and you're using extended oil changes...if you have an engine problem you may/will be denied warranty coverage.

I know at least one guy that buys a new car every 4 years...drives about 20k miles a year......and changes with synthetic oil every 3k miles. Kind of overkill and a waste to me. And how many people keep their vehicles over 200k miles? Less then 90% of all new vehicle buyers DON'T. So if you fall into that category...then why spend the extra money using synthetic?

 

[BlackWorksInc]

As was pointed out earlier, "Synthetic" in the NA market is a very loose term. Most "Synthetics" are actually a blend, often Base Stock III. True Synthetics are made from Base Stock IV & VI (V is sort of a "doesn't fit any category" dump spot for Nissan oddball mineral oil and such).Synthetic oils have been proven to provide better protection and performance in engines that can truly take advantage of it. Modern engines (particularly those running synthetic from the factory) tend to have extremely tight tolerances and need a very uniform molocule that is only really attainable from a synthetic oil, another good reason is most true synthetics tend to last longer than most conventional oils (there are always extenuating circumstances and oddballs to the rule).

I run Amsoil Signature Synthetic 5W-30 (says its good till 20k under normal driving and 15k under "severe" driving "gaurenteed") and I'll probably send a sample in at 10k (just hit 5k on it) to see how well its holding up.

Point being, synthetic will hold up a bit better than conventional dino-oil, but really most dino-oil now is pretty damn good to begin with, it just comes down to what you want to spend. Penzoil isn't as waxy as it used to be, we run it at the dealership and its done pretty well.

As long as its SAE 5W-30 and meets or exceeds API Standard "SL" then you're golden!