Regular motor oil versus synthetic for my '96 4.6L LX

[Leannadanna]

Hi guys!

I've searched this and other forums and found some relative info for other years and motors, but nothing specific to MY year and motor.

It's time for an oil change. I've owned my '96 4.6L LX for almost one year. The oil change/tune-up was first thing when I got her... regular gasoline-engine motor oil.

While calling around for the best oil-change deal today, I heard about something new to me... a combo regular/synthetic blend oil change. I have already tried to learn about the difference between the two and know synthetic is supposedly better for high-mileage cars. Also learned that you can't just "switch" from regular to synthetic, or at least you SHOULDN'T. Also learned some new cars come out of the factory using synthetic.

My questions are these:

1) With 196K miles, should I be using synthetic? If so...

2) How do I safely make the switch?

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[bctbird]

Synthetic is better for newer and older engines, can be changed or mixed with conventional at any time (if you think about it the blend is a mix of the two) and keeps your engine cleaner. Can never hurt to use it.

 

[Leannadanna]

It makes sense, but there must be a reason I have been mostly discouraged from switching. Just now it occurred to me that I misunderstood - it's really just that I can't go back and forth. Once I switch, stick with it and all will be well?

Thank you!

 

[Bcn]

It doesn't matter if you go back and forth, or strictly usr one or the other, the only thing is synthetic doesn't break down it's viscosity as fast as conventional, so you can go longer between oil changes, synthetic can handle higher temps without thinning out or losing viscosity. I'm guessing the advice not to switch back and forth is so you don't get used to changing your oil say at 7-12k miles with synthetic, then go back to regular and keep same oil change intervals. regular oil breaks down faster so needs to be changed more often. typically at 5k miles. but can break down faster or slower depending pin how you drive, temperatures, towing, or climbing hills if you live or drive in mountain areas. hard driving I change synthetic at 5k if mostly hwy I go to 7k. mobile one just came pit with any oil that supposedly lasts for a full year lol.

 

[Curt]

It doesn't matter if you go back and forth, or strictly usr one or the other, the only thing is synthetic doesn't break down it's viscosity as fast as conventional, so you can go longer between oil changes, synthetic can handle higher temps without thinning out or losing viscosity. I'm guessing the advice not to switch back and forth is so you don't get used to changing your oil say at 7-12k miles with synthetic, then go back to regular and keep same oil change intervals. regular oil breaks down faster so needs to be changed more often. typically at 5k miles. but can break down faster or slower depending pin how you drive, temperatures, towing, or climbing hills if you live or drive in mountain areas. hard driving I change synthetic at 5k if mostly hwy I go to 7k. mobile one just came pit with any oil that supposedly lasts for a full year lol.

For your high mileage engine, as with my low mileage 97 281 ci I use Royal Purple Full syn. Several mechanics tell me NOT to switch back and forth from petroleum based ( regular oil) and full synthetic (derived from natural gas) full syn has less friction and coats ALL surfaces, and has no build-up like most regular oil. Castrol makes an excellent full syn 20W50. Do whatever you feel is right though----good luck!!

 

[64ZCODE]

Hi all. I hear the precautionary statements as everyone does about switching to synthetic motor oil, but I think these are old wives tales that might have been valid for the low viscosity synthetics that were originally introduced. However, synthetic oils have changed and improved over the years and are available now in higher viscosity ranges.

I tend to run and maintain older cars and get them to go as long as I can. I learned that from my father, a child of the Depression. I have a '90 Mustang 5.0 LX with 320K miles on the clock. I converted it to Castrol 10W/30 full synthetic at 220K miles and have had no problems with leakage or blue smoke. I made the switch because of an article in Mustangs and 5.0 Magazine on the benefits of switching to synthetic engine oil. They included dyno tests demonstrating an average increase of 5 HP at the rear wheels after converting to synthetic, so you know there's less friction in the engine and it'll last a lot longer. At the last oil change, I converted to Mobil 1 15W/50 full synthetic and the engine continues to run strong with no issues.