I have always put synthetic in my 05 6S, but I found an article the other day that found in normal everyday cars, synthetic isn't actually protecting your engine any better as long as you follow normal changing guidlines. Synthetics are better oils but unless you have a race car, high end sports car, or do seriously heavy driving in bad weather conditions conventional oil is just fine. I will probably switch over to semi syn for my next change seeing as it is about 1/2 the price.
The article also states that test results show synthetic oil filters are no better than any other oil filter, but does warn to stay away from the "cheap brands" However the stock oil and filter put on our vehicles are Ford Motorcraft and that is labeled as a "cheap brand" out in the world. If you were to go to the dealership that is what they would use.
I have used everything from Valvolene, Pennzoil, quakerstate, to me I don't notice a big difference, oil is oil. Mine is a daily driver with 61500 miles on it and I haven't had any problems yet. But again I am probably switching to semi-sny after the article I read, better than conventional but not the high cost of full syn.
The problem with semi-syn engine oil is that it is not very cost-effective for what it is.
I mean being only 1/3rd synthetic, one would expect it to be roughly 1/3rd the cost of a full synthetic. It's not. In most cases it's 7/10ths to 4/5ths as much as it's full synthetic counterpart.
It won't stay in grade significantly longer than a conventional. Certainly won't stay in grade longer than a full synthetic. It's just not cost effective.
I've used semi-synthetic, but I got several cases of it for $1.79 a quart when I was still driving my 200,000+ mile Integra. I was just dumb-luck that it was a really highly regarded motor oil on BiTOG. (Phillips Trop-Arctic)
Another thing to consider, your car is pushing up on 8 years. I don't know the condition of your engine. My 3.0 is the cleanest engine I've ever owned. There is not a hint of sludge or yellow oil varnish or anything in it. The cast parts are nice and grey the machined parts are shiny and silver. I don't think I would have any problems with switching to a synthetic now. But in some older engines, the sludge is the only thing keeping them from leaking. Synthetics have a way of working around the sludge. All the sudden you have a $6.00 a quart leak where there was no leak before.
Lastly, on conventional oil brands; I don't think that Castrol, Pennzoil/QuakerState, Mobil, or Valvoline knows anything about oils that the other major brand names don't know. I choose Valvoline because it comes out of the bottle the lightest/clearest/cleanest color. By comparison Castrol is super dark. I know that has no bearing on how the oil works. I just like it that way
The car is almost 8 years old, but it only has 64k miles on it. And it has been taken VERY good care of. Everything is clean. Evey one that sees it, says it looks new. So I am guessing that the engine is in great shape too. It drives like it is in great shape.
It is in such good shape that I want to do whatever I can to keep it that way. So if spending extra on synth oil is worth it, then I will be happy to do so. But if it is just overkill then I will skip it.
BTW spazdog, I see that you get 24.8 mpg with your 6s. Everything I had read was that the 6s gets only 20 or so mpg, but when I just checked my mpg this last time I was getting about 24 mpg as well. I am very happy about this, but I was a little confused until I see that I am not the only 1 getting the better mileage. Was I reading the wrong model or something? Cause I swear I read in a few places that the 6i got around 24 or 25 mpg and the 6s got only 20 mpg.
^ on the MPG, Most of us that I see get upwards of 24-25 avg, Mine has been around 24.5 with the highest ever of 26.
I have seen many reports as well say the car "should" only get around 21, I wouldn't be bothered by that. It seems to me they did the sheets wrong when the car came out. I have NEVER had worse then 22 MPG, even in winter with snow and slush on the road, and I don't do many highway miles either.
I have read several articles online that say if the car is new, or high miles you DON'T want to use full synthetic. My suggestion, don't take our word for it, You should always read as much as you can and make your own mind up. That way you are well informed, you educate youself on the topic, and not just blindly follow someone on a forum. You don't know anything about me or how I take care of my car.... Why would you take my word for it? Google "synthetic oil" and read 3-5 TRUSTWORTHY sites, they will give a good explanation and then you can decide what is best for you and your car.
After reading above what Spaz has to say I will revisit the semi-syn as well. I havn't looked into how much they actually cost but I know they are cheaper, If they aren't any better than conventional why pay for more than conventional. That being said I have never put conventional in my car but I know I don't need synthetic either.
When I do average 21-22 it's almost exclusively city mileage or I've been trying to punch a hole in the floor with the accelerator pedal a lot. :lol: I don't think I've ever gotten below 21. There maybe a benefit to having a 3.0 in a crowd of 3.5 V6es.
I'm not against semi-syn. I really liked the Phillips 66 Trop-Arctic semi synthetic. But virtually every semi-synthetic I've seen is only 1/3rd synthetic and it's only usually about a dollar or so less than the full synthetic. If there was a bigger margin in the price difference, I would use it (If I could still get the Trop Arctic semi-syn...) But I'm not really able to extend my oil change interval on it any over Conventional. Just feels like throwing money away to me knowing that for around $6 more I could have had a full-synthetic oil change.
I'm sure someone can correct me about how much better semi-synthetic is over conventional to justify the price. My opinion isn't entirely scientific. It's just what's working for me. :laugh:
I did find Quaker State Synthetic at Oh-No-Zone for $1.99 a quart on clearance.... we'll see if mt SRT/4 powered clown hearse blows up on that :lol: