speedzer

No one has mention whether it was safe or not to switch back to conventional oil if currently using synthetic.

Black Tire

my dad is sp cheap that he buys the cheapest non brand name brand oil from any dept store for his 1990 Accord. The car still runs great...he just changes at 10k intervals.

fla-tls

FYI - Porsche Boxters are known for having engine problems (blowing them - many times with much less than 100k miles on them). Porsche charges about $20k a pop for a replacement Boxter engine that's out of warranty.

IMO - Porsche is not a good example.

I run Amsoil 5w-30 on 10k intervals. 3k intervals are crazy, but I do want the synthetic oil because they tend to last better/longer. Granted, at 10k intervals you're kinda in the grey zone as to whether or not synthetic is required over regular dino oil.

Crazy Bimmer

Audi was telling people to change every 10k on dino.

Well, that was till the whole oil sludge issue. So dont always go by what they say.

Now its every 10k with synthetic but my audi tech told me to do it every 5k. Personally i think they say to do it every 10k miles because they offer it for free. It seems like thats when they started telling everyone to do long intervals.

fsttyms1

15k intervals on the TL. 200k trouble free miles. Get a oil sample kit from blackstone and next time you have your oil changed get a sample taken and tested. 5 k is a waste. I was getting the same results at 15k as regular oil was getting at 7500. Both were able to go much further

Yes it is

Costco

Anyone? what about Mobil 1 high mileage?

If it matters, there's this guy with a Del Sol with 300,000+ miles (who knows what he has now), every 3k with synthetic IIRC. Honda offered to trade him ANY vehicle in their current line up if his motor/car lasted until 500,000 miles.

Here's a page I found with info concerning synthetic vs. dino oils.

http://forums.yellowworld.org/showthread.php?t=1136

Really interesting. The guy who wrote the bolded text is a NASA Engineer who studies the properties of lubricants. He recommends that you DON'T run dino (mineral) oils for more than 1000-2000 miles between changes.

Then he mentions piston ring seals in new motors, which has been a huge debate concerning the break-in of new motors. He recommends using single weight mineral oil (he specifies Havoline 30) for the first 2000 miles, then to switch over to synthetic. He mentions that Corvettes come new with Mobil 1 in them, and people brought them back to the dealers because they were burning oil.... but I personally think that its the dumb Corvette owners who aren't breaking in their engines properly.

Then he makes another point which is confusing: he says to avoid running multi-weight oils for more than 2,000 miles, but then he said its safe to run Mobil 1 for up to 10,000 miles. Doesn't Mobil 1 only come in multi-weight?

This article also recommends using dino oil to break in your engine, found under the section "Conventional Oils"

SpeedyV6

fwiw, here's a primer on motor oil put together by a retired physician who is an ardent auto enthusiast. He may not know nearly as much about oil as a tribologist but it makes for an interesting read. The guy is a big proponent of lighter weight oils:

http://63.240.161.99/motoroil/index.html

hemhaw

In most cases, using syn is sorta like using nitrogen in your tires. Is it better? Yes. Will it make any difference in the long run? Nothing you can measure.

Costco - use the cheapest stuff you can find, and just change it regularly. If you are worried about usage due to engine wear, go up a weight.

SpeedyV6

That article also makes this claim:
I've never heard or read such a thing before. While it sounds nice to think that the additive package for each motor oil is uniquely optimized to its base oil, I have a hard time believing that one brand would be incompatible with another, especially if they are of the same viscosity.

Leo Type-S

haha i have a friend like that..