Can I go back? syn---->reg.

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May 9, 2003
Fayetteville, NC
Hello all, I need your advice/thoughts on this: I bought my Ford T-Bird(1997, 4.6L) with 72,000 miles on it, and used mostly 10w-40 regular oil(motorcraft/pennzoil). It never used any oil between changes, never had to add, and the level was ALWAYS perfect, never dropped a bit.( I drive about 60 miles a day, and live in TN.) At exactly 82,000 miles, I decided to switch to synthetic, and put Pennzoil full synthtic 10w/30 in it. After about a week/300 miles, I noticed a very slight drop of the level, perhaps 2-3mm . I wasn't scared, 'cause I knew it was usual for syn. oil to be "used" more than reg. oil, 'cause it's "slicker" and that I was also using a lighter weight. However, after 2,600 miles on the syn. oil, the level dropped further, and came down to the exact middle between the "add" and "full" marks.(I had to add exactly a half quart, and after that it's fine, the level I mean). this scared me a little, although the car ran just fine, and i never noticed anything abnormal. I talked to several knowledgable people and all told me it was normal to use a 1/2 quart in 2,600 miles, especially syn. oil. I checked for leaks, and didn't see any oil drops on the ground or on/in the engine., so it seems, that the syn. oil was "used" more than the regular oil. Also, the syn. oil looked a lot dirtier, and I'm happy about THAT, 'cause the experts tell me that it has "cleaned" the engine more than the reg. oil. Can/should I go back to my regular Pennzoil or Motorcraft 10w-40? Have I created leaks that I cannot see somehow? Or was that amount of oil jsut "used"? What do you guys think? If I go back to reg.oil, should I use a "high mileage" type? Any feedback is very appreciated... -Nishan.
Why don't you try a 40 weight synthetic. Perhaps it's just the viscosity that caused the oil to be consumed.
97tbird, It is amazing the stories that have been propagated in reference to synthetics. First of all, with a healthy motor, and using a synthetic of the proper viscosity, you should actually use less oil with a synthetic because it doesn't burn off or vaporize as easily as dino. In fact, one of the selling points for people with a "green" perspective is that synthetics are less volatile and create less pollution. I'm not sure how much stock I put in the impact created, but that is what is promoted nonetheless. Second, you have not "done" anything irreversable to your engine by putting synthetic in it. You CAN go back to dino with confidence. I have, for various reasons, put dino in a car that has been living on a steady diet of synthetics with never a problem. I will also tell you that I have put synthetic in cars of varied make and some with high mileage and have never seen the consumption problem that some describe due to its "thinness" or "slipperyness." That is not to say it can't happen but I have never seen it. Obviously I have not seen every oil/motor combo but I have certainly seen enough to make a confident assertion. I hope this answers your question as well as helping you to understand the misunderstandings that have surrounded synthetics. I believe there are still stories being circulated from the time synthetics first debuted and had some growing pains. PS I think maybe some of these stories came out of people trying to put oils designed SPECIFICALLY for jet turbines in automobiles...different "algorithms."
It's not unheard of for engines to consume more oil for the first one or two oil changes when switching to synthetic. It cleans out some of the crud that's been sealing things, and it takes a short while for the real seals to seat themselves again. It's very uncommon for engines to use more synthetic oil than regualar oil for any length of time. Ken
97tbird, the last time I had a car with a V8 engine I would have been really happy if it had only burned 1/2 quart of oil in 2,600 miles. If you continue to use oil at this rate then I would suggest using 0W-40 Mobil 1 or any Synthetic 5W-40 oil you can find and that should reduce your oil consumption to what it was before you used Syn oil or even lower. I am certain that changing over to Pennzoil Synthetic oil has not done any harm and any increase in oil consumption is most likely caused by the lower viscosity. I do think it is a good idea to use an engine flush, AutoRX or Neutra 131 before using synthetic oil in a high mileage car for the first time but I doubt that not doing this will do any harm. I would suggest not leaving the Pennzoil Synthetic oil in any longer than you would have left the old "dino" oil in for the first oil change. Then if you want to for any future oil changes leave the oil in longer. If this were my car I would try to find a 5W-40 ACEA A3, B3 rated synthetic oil on sale and then use this grade. You will probably not have to add any oil in 3,000 to 5,000 miles. Pennzoil, Valvoline and Chevron all make this grade of oil and I have seen it on sale from $3.37 to about $4.49 a quart. Castrol also sells 5W-40 but only at VW/Audi dealers and maybe at some Mercedes, Volvo and BMW dealers. [ July 27, 2003, 01:00 AM: Message edited by: Sin City ]
You never ran synthetic in the first place my friend. Your so called "synthetic" is in fact reworked Dino. It errks me how Castrol was able to dupe the public on the Group III definition. So for you it is a zero sum game.
Pennzoil synthetic isn't a true synthetic either, as I recall. I'd recommend using the Ford-recommended weight, 5W30 as I recall. Use a true synthetic such as Amsoil, Redline, or Mobil1, or a good dino oil such as Chevron, Pennzoil, or Castrol. I used Chevron in my '94 T-bird 4.6L V-8 and it worked great. If you want to go synthetic I'd recommend Mobil1 5w30.
YZF, I stand on my previous statement At exactly 82,000 miles, I decided to switch to synthetic, and put Pennzoil full synthtic 10w/30 in it. No such thing as Pennzoil 'FULL SYNTHETIC' The guy should have run Mobil 1 or something and then posted this question. Therefore I stand, Pennzoil is a hydrocracked crude...Group III. Not a PAO or Ester formulation.
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