Oil change....mistake???

[Kanndykisses]

I recently flushed the engine, changed the oil, etc (among TONS of other work)...went to Mobil 15w50 Synthetic (I wasn't running a synthetic before, but the old girl's got 140K now, so...) Now I'm wondering if that was such a good move, I've since heard some complaints about loose deposits and cars running hot. Anybody else run it, and any opinions? So far she seems to like it, purrs like a kitten for now.

[fajita23200]

I've heard nothing but good things about synthetic oil. I've also heard good things and bad about slick 50. I know a guy who put synthetic and slick 50 in his 90 Camaro 2.8. It has almost 200,000 miles and still going strong.

[cujotom]

synthetic oils have come a long way in 30 years. i have talked to an engineer who says on newer cars it is the cats meow, on older cars
( higher miles ) he would stick to a regular petroleum based oil, why mess with what has worked thus far? on the other side of the coin, i have spoken to mechanics who say that it works just as well on higher mileage cars. the nice thing about synthetics are there extended drain intervals, than there is the cost ( pricey ). i worked years ago at a plant in pa who packaged oil, they told me that oil is oil! period! yes this is a tough decision. in my opinion i would stick to regular maint with a decent brand of motor oil, every 3000 miles. its funny how cars for the most part last a very long time with proper regular maint. we all want some magical oil or part or this or that to make it last longer.stick to the basics. another opinion, stay away from those motor flushes! alot of your leaking problems are due to adding those cleaning agents into your crankcase. if you dont have leaks now, you may end up with them. motor oil has agents to clean all by themselves... a friend of mine recently told me ( IF IT AINT BROKE, DONT FIX IT ) STICK TO THE BASICS... GOOD LUCK!

[petey_z24]

syn oil tends to find its way thru old gaskets when being put in a high mileage engine that had been running dino oil before

[C_Sephiroth]

The newer Synthetic oils are no worse than a Petro based oil about causeing leaks. I use Mobil 1 in all of my cars, it is great. Indeed stay away from engine flushes. bad bad news

[Three_Fingers]

/me agrees withC_Sephiroth on the flushes...if anything's gonna do in the seals-flushing will-it softens them so that cold oil pressure (which is higher than hot oil pressure) blows them out.

I run Castrol Syntec in my 2.0 and it seems to maintain it's viscosity on hot days idling in traffic whereas the dino oil would thin out and make the oil pressure light flicker at idle.

[Kanndykisses]

"i worked years ago at a plant in pa who packaged oil, they told me that oil is oil! period!"

Sorry, but I beg to differ...in my opinion, synthetics protect much better and run much cleaner in the long run. I also work for an oil company, and we have great heavy duty synthetics, but we have no product yet that compares to the 15w50, so I basically took a chance on putting it in my car. The benefits from running synthetic definitely outweigh the cost, that much I'm sure of...but what I'm not sure of is whether my old gaskets and seals can survive the change! I did have the head gasket replaced a couple of years ago, and watching for any leaks....so far, so good. Sitting in traffic (2 hours+ per day) in afternoon heat hasn't really made a difference, although many ppl have told me that they've had their engines running really hot after switching to 15w50. I do alot of both city & highway driving, and we'll see how long I can go before I need my next oil change. I do know that now that I've switched, I'm basically stuck with the synthetic...no more flushes for this old girl!

[cujotom]

sorry, i didnt fully explain what i was saying. as far as the statement that i made pertaing to oil being oil was about std type motor oils, not synthetics! just a thought... if you work for a oil company why are you asking ( in this forum ) if you made a mistake in doing what you did.i would assume that you could have asked the people you work for, and maybe even have gotten a knowledgeable answer. i mean you did the oil change first! than you wonder if it was wrong! that kind of back yard mechanic stuff can be extremely costly. get the pros and cons first! than decide.best of luck with the synthetic change...

[sweetwhiteCAV]

I use a Synthetic Blend and I havent had any problems, in fact , and this just might be all in my head, I feel a little better throttle response and high end power...

[Kanndykisses]

Thanks for the replies! Actually, I did ask everyone at work their opinion of synthetics before the change, and it was highly recommended, but not one person was running 15w50 in their cars. I figured I'd get some honest-to-goodness opinions from those who know best...the ones who actually use it in their vehicles. And we don't have a comparable weight, either...ours are mostly for diesel engines. I knew I was going to switch to synthetic anyways, but only afterwards did I hear the complaints about the leaks, etc. I've since decided that it was a good idea based on some of the opinions I've gotten here...thanks!

[GRANDAMLD9]

The best easily available "off the shelf" oil you can get is Mobil 1. No ands, ifs or buts.

It's a PAO Group IV FULL synthetic like full on race oils (such as Amsoil, Royal Purple and Redline). The VAST majority of other synthetics on the market (such as Castrol Syntec, Valvoline Max Life etc) are all now Group III oils, which are essentially "cracked" group II fossil oils.

Either way, unless you have a hookup for Amsoil, and a place that can order it, your best bet is Mobil 1..........



Now, if you are cheap and/or a more "normal" driver and don't want to pay for a full synthetic, Most name brand Fossil oils are almost the same. Castrol GTX seems to have a slight advantage over other conventionals in performance oriented applications since it reportedly has a high flash point and better high temperature performance, but still not even on the level of a Group III synthetic (let alone a Group IV).



And do NOT bother with synthetic blends...........they cost almost as much as some full synthetics, but offer only about 5% more protection than a good conventional oil.


Here's a nice article that might help you decide if synthetic oil is for you: http://www.csaa.com/global/faqdetai...257C220,00.html



One final thing..............do NOT use oil additives (Slick 50.....Prolong etc). Over time, they are one of the WORST things you can do to the internals of your car.

[sweetwhiteCAV]

yeah i used Castrol Synthetic Blend 10w30 it was about $0.50 more per quart than convetional Penzoil.... and Im really happy with it...

[lapspec]

I agree with GRANDAMLD9 the best way to go is full synthetic such as Amsoil in fact I am a dealer. want more info visit my site www. synthetic-lubricants.com