The98Stang

Over the next few weeks I plan to drop the oil in my 98 GT. Car has 97,000 miles on it. Am I better off with synthetic or just run conventional oil? My daily driver is lease so I dont give a crap what goes in it. So its been a while since I cared about a car

CalBoy101

I'm naturally a skeptic and have been slow to adopt synthetics, I know its better but wasn't convinced that it was better enough to warrant the extra dough. I also tended to follow the "thicker is better" mantra, for exampling running 10-30 or 10-40 oil if the engine was spec'ed for 5-30 oil.

A couple of things have turned me around on this. Some recent tests I saw comparing different synthetics and mineral based oil made a dent on me, the performance of the synthetics was impressive. These tests showed that the tree hugger driven loss of zinc in non-racing motor oils wasn't really an issue anymore as the current synthetics don't need zinc to work well. In particular the performance of the 5-30 Mobil 1 synthetic oil really stood out.

Also the price difference of synthetic to mineral isn't as large as it used to be, I think because more people are switching to the synthetics and less are using mineral.

Regarding oil thickness, I used to mostly run older cars that were either drinking or dripping more oil than a new one would so the thicker oils were helping me on that one.

But now I'm finally dealing with cars that don't excessively consume oil so I don't have to lean on the thicker stuff anymore.

Also with a newer engine running the thinner oil helps with cold startup engine wear so I'm no longer going the thicker is better route.

So I'm a Mobil 1 synthetic 5-30 wt guy now. Its a very good oil and is easy to get, Napa here often has it on sale.

TheDullahan

I also vouch for mobil 1. It is great oil. The hell I put that stuff through in my supra and it holds up. It is all I use.

Stevo86

You're 4.6 should be running 10w-30. Ford only specified 5w-20 to gain a few 10ths of a MPG. The engines outside of the US all call for 10w-30.

If you really want the low down on oil check out bobistheoilguy.com that guy knows his stuff and the forums there are packed full of more info on oil than most people without a chemical engineering degree understand.

antwaan

I use Valvoline Max life in my Mustang (135k). I used to run full synthetic but It leaked oil and when I switched, I don't leak a drop. I put Mobil 1 in my Tacoma.

CalBoy101

I could see running the 30 wt on the high end but its appearing to me that there is no disadvantage in running 5 wt on the low end and it can help you with better lubrication during cold starts. Some claim that 5-30 Mobil 1 is actually thicker than 10-30 Mobil 1 at high temps although I'm not quite following the logic on that one.

TomKat

id run conventional oil unless its a v8 or your pride enjoy good ol dino oil be just fine

stillahotrodder

I use Mobil 1 because it is a good lubricant and because I can go twice as many miles between oil changes,6000 miles vs 3000 miles.That means less times starting the engine and waiting for the oil pressure to become normal.Better for the bearings I believe.

Sonic Mustang

That makes absolutely no sense whatsoever.

Are you trying to say a synthetic oil flows better when cold?

Stevo86

I believe he means that if you double the service interval on your oil change you cut the number of times your engine starts without oil pressure in half.

Makes pretty good sense if you think about it instead of trying to be a douche all the time...