What do you guys think ?? I am going to do my oil change this weekend and was thinking of synthetic oil for less friction. I have a 94 with a 4.0 and auto trans with 148K miles on it. Should I stick with a thicker oil....or go with the synthetic for improved economy ?

 

You could go with synthetic in a heavier grade if you need the thicker oil. My brother switched his 4.0 to Royal Purple 10-30 at 183K, and loves the difference.

 

Ok well I may do that.....I just want to have the engine run as smoothe as possiable, along with that I think you can pick up some fuel economy and better performance as well, I was also thinking of an underdrive pulley set as well, but I dont know if they make them for our 4.0

 

I think I can add a little insight because I just made this decision a couple weeks ago. My truck/motor is older with more miles and I wasn't sure if I could switch. Any car can run synthetic. The oil is just thinner and cleans out the motor better. It does not cause leaks, but if you already have a leak that the dyno oil is plugging, the synthetic can clear that out and the thinner oil may leak through. For the first time running full synthetic its suggested you change the oil at 3000 miles instead of 5000 because the oil will most likely be rather dirty from all the crap the oil cleans out of the motor. Also expect to go through some oil the first two weeks. With higher mileage motors the tolerances aren't as tight and the thinner oil can leak by the rings and burn off some. This isn't supposed to last, just takes a little time for the synthetic oil to condition the motor. So far in my truck i'm very happy with it, truck runs a little smoother and quieter, as well as starts up quicker. I have experienced the initial loss in oil, but that has flattened off and i'm not losing any oil any longer. Good Luck deciding.

 

Sweet.....I will go for the Synthetic !! As for now my truck parks in the garage every night and there is not ONE drop of fluid on the floor....we will see if this contenues after the switch.......How much did you go through in those first few weeks ???

 

I went through 1.5 quarts, and the two weeks is just a general thing, depends how you drive and how far. I would just make sure to check it often at first just to be sure. BTW I did have a slight leak that contributed to the 1.5 quarts. Also make sure u get a synthetic oil filter as well.

 

10w-30 mobil 1 is what I'd use for your application.

btw, Pure synthetic oil cleans better and suspends the particulats better. Might wanna change the filter a few times during the first 5k miles.

Rich

 

Ok......so there are spacific filters for the synthetic oil as well huh ??? I have always used traditional oil so I am new to the synthetic idea

 

Why are you guys saying synthetic oil is any "thinner" than regular oil?

It has better detergent properties, so like my91ranger said, if you already have a leak clogged by sludge (from conventional oil) then that leak will be cleaned and you may get a leak...but that doesnt mean you should keep running conventional oil, that was just a problem that was waiting to happen anyway. Fix the seal and run the superior lubricant.

Thick and thin has to do with viscosity (ie, oil weight). 5w-30 is 5w-30 no matter how you slice it. Conventional oil is more likely to cause sludge and get thicker... but sludge doesnt so much for lubrication in your engine.

The owner of my truck before I got it ran conventional. Even with only 37,000 miles there was a good ammount of sludge in the engine. I have ran it on Mobil 1 5w-30 since and ran FRAM oil filters (no, they arent bad filters, that story was 100% slander). Now when I change my oil every 7,000 miles it is just a really dark brown. No sludge, no black, no chunks. Every few oil changes I slice open my filter and look at what it is filtering too.

Go synthetic. Why anyone would run anything else is beyond me unless you like doing oil changes.

If I ran conventional oil I would be changing every 3-4,000 miles. So the extra price of synthetic balences out with the longevity of the oil. In reality, you dont ever HAVE to change synthetic oil if you keep a good filter. I know a guy who ran 100,000 miles on the same oil in a turbo diesel. He changed his filter and topped her off every 5,000 miles. That's impressive.

 

WOW !!!!! That is great news, I think I will go syntheic in the differentials as well !!

 

If/when I ever change my diff lube I am going to go synthetic there to. I plan on doing an explorer swap at some point in time so I'm in no rush.

I have a manual tranny, but if I had an auto I would've changed that fluid to synthetic as well.

 

I do have an explorer diff....well I think I do because I have rear disc breaks....as far as the trans goes....with 148K I am thinking I should not mess with the trans, those E4OD's can go out at any time !!

 

I bought my Ranger with 192K on the odometer and changed the oil not long after with Royal Purple. There is a noticeable difference in start up and even feels like a little extra power, though not much. Didn't develop any leaks and didn't even burn any oil. Also used a K&N filter. Don't think I'll ever go back to conventional, the synthetic just works too well.

 

Ok so any trouble with the trans yet ??????????

 

My wife's Hyundai Accent has 108K on it and had it's 6th oil change done yesterday. Mobil1 and Denso filter. Thats all it's ever had, and I can attest to how well it has protected that motor.
Synthetics FTW!

 

Well it does have like I said 148K on conventional oil......it will be nice to see hoe much sludge gets washed out of the motor with the use of the synthetic oil after all that time.

 

Depending on how often you changed your oil with conventional oil you are likely to be extremely surprised. You oil will look dirty by 1000-1500 miles. Check it every 500 or so (every two fill ups is what I did) to guage when to change it to flush all of that crap. After two or three you dont have to sweat it, just change every 7,000 or so.

 

Thats great.......I think I will do a complete tune up as well....I just bought the truck 2 weeks ago and I do not know its history, so time to go through it all I think.....although it runs fine, I just like to start with fresh parts so I know how old they are

 

just don't bother with synthetic blends.. they only need .05% or 5% synthetic to be called a Synthetic blend.. paying more than conventional for no real benefit.

 

I run motorcraft synthetic blend 10-30w,Ill switch to full synthetic when I hit 80-90k.

 

lots of people are using Mobil 1....I think I will stick with that one !!

 

So do the “5R55E’s”.