IMO, as long as you're a nazi about changing your oil every 3000 miles, normal oil works fine. I change my oil every 3k, and even if I switched to synthetic, I'm in such a habbit of changing my oil every 3k, I would probably have a hard time breaking it.

I starting using systhetic in my 99 Mazda Protege around 20k and then at 70k it sprung an oil leak at the main seal. I was told at the dealership that the Synthetic caused the problem. I did not have it fixed due to the cost and drove it until 81k and traded it for the Alero. I decided I would not use synthetic with the alero becasue of the leak problem with the Mazda. Plus I got a 100k warranty with the Alero so as long as I change the oil every 3k, I don't care if the motor blows because it will be fixed for free :thumbsup: .

How was your protoge compred to your ECOTEC alero? Quicker? Better handling?

HAHA...good question. The protege had a 1.6L 105 Hp motor. I guess it goes without saying it was a VERY SLOW car. The Alero Ecotec is much much better in every shape and form then the Protege was. It was a great car at first, then I started putting alot of miles on it going to college, and it started having very expensive problems around 65k. It was better of trading then paying $500 for one sensor and $1000 to fix an oil leak. But all around the Alero is made much better.

My uncle complains about this happening on his international, (conventional OK, sym leaks) but I think it has more to do with parts warn past tolerences, not the seals. I have NEVER heard of syn causing seals to fail, only to identify questionable seals due to the fact that it just goes everywhere it can, an excellent quality for a lubricant, especially in a well sealed engine where all the connections are within tolarences.

who says told you 3K, the oil CO? hmmm wonder why they would tell you that.... :huh?:

I do mine at 5K and GM even says you can go as long as 7500 miles (in the manual) as long as you don't drive in high revs often you should be able to do 5K miles easy, even on dyno juice. of course you can do it more often if the spirit moves ya.

I agree. I am not sure the reason that most dealerships say you should not use it. I think my mazda just had a seal problem and the Syn. may have made it worse as it got older. I would use it in my alero right now had I not spent $1000 on an extended warranty. Because the Alero is gone out the door before that warranty runs out. So there is no point spending the extra dough on the good oil when the warranty company says just change the oil every 3-4K. I really do think it helps a motor last longer and stay much cleaner inside from sludge though.

I won't use anything but syn in my engine, but that's what it originally shipped with. This may be due to the fact I'm in Alberta and it helps with those cold engine starts when it's so cold, penguins call you crazy for going out. I remember being surprised when I brought in my vehicle and saw them putting in synthetic.

I think that also makes the most sense for those vehicles equipped with the GM Oil Life System, since if that system tells you your oil is still good after 8000k since the last oil change, it must be calibrated to the average breakdown of synthetic oil. I haven't seen a conventional oil that lasts nearly as long under good driving.

New engines do NOT come with synthetic oil.

The GM oil life system is calibrated to conventional oil; syn does not break down anywhere near 7500miles, unless its under VERY stressfull conditions, like driving constantly in high heat at 5K RPMs.

I drive fairly hard, and in NJ stop-an-go traffic...

I agree with Fast Eddie. The only real difference is that synthetic oil doesn't break down nearly as quickly as conventional oil. By my understanding if you could run a motor under ideal conditions (highway speeds for 8 hours a day) you could easily put 25 to 30k (15k to 20k miles). But, synthetic has to be changed fairly regularly anyway because of the cold starts. Cold starts causes a lot of gasoline contamination.

The myths of switching between oils is just a myth. You can switch between oil changes no problem. You just want to make sure that you still have a similar weight of oil.

I would guess that dealers have learned over time that if they suggest 3k (for me in Canada 5K) oil changes that you will bring them in by 5k. Plus it's the worst case scenario so it covers their butt. You can't go wrong by changing oil to soon. And of course, it's more money in their pocket. So they basically can't go wrong by suggesting to change oil early.

read my post above about NASCAR guys going 300+ miles with the oil temp pegged. I don't think speeding from stop light to stop light is as harmful, but you should be OTAY with 3K oil changes :)

As for the gas contamination, that's a new one on me. MY oil in any car has never smelled like gas. The only reason to change it is cuz it gets dirty, worst case scenario IMO, is you clog the filter :o

Great article on engine oils, grades, synthetic vs mineral:

The Engine Oil Bible

I have a 2001 gx with WAI, 62mm TB and 109783 miles on mine and I've been running Mobile 1 since the first oil change at 3,000. Now I change it at the idiot light interval and all is well. When I first did it I noticed the engine would rev easier. I recently started adding Engine Restore and it appears to help. I notice when the oil needs changed. About 3-4000 into the new oil I notice the engine doesn't quite feel right.(not as strong)could be just me. I think I'm going to try and change the oil every 4,000 instead of every 6000. Car still runs great and strong.

Man! That bible sure has a lot of info. :eek:

ive decided to stay with regular oil, because my car has 50,000kms on her and i dont want to risk fooking a seal or something. That page really does have alot of info!