I don't know about that, but it seems like I've been under my car 3,000 times this year....does that count? Surprised the town hasn't taxed me for having it as a permanent fixture of my garage!

 

What kind of contamination are you talking about? Because if your engine is sound (rings are in good shape that is) and you've got a good paper air filter, then you won't get much contamination in your oil. Oil analysis also shows this too, as they test for fuel, water, antifreeze, dirt, and all the wear metals too.

I agree that startup wear is a big factor, but it's not even close to being 99% of the wear in an engine. An engine has almost no wear once the oil is warmed up and at a steady speed, so the rest of the wear occurs during acceleration and during cold operation. It's split fairly evenly between those two factors actually, which is why the hot viscosity of an oil plays a big factor in wear numbers in oil analysis reports.

It's all about balance, you want an oil that is thin enough on startup to flow well, but you also want it to remain thick enough when hot to provide a good layer of protection too. Not every engine has the same needs too, tighter clearance engines need thinner oils. Which is why the LT1 is a perfect candidate for something a bit thicker, since it's clearances are not as tight as many new design engines. And when you've got higher mileage too, those clearances will open up also.

Like I've said here many times, oil analysis is your friend, it helps you determine exactly which viscosity is right for your driving style, climate and engine, without any guesswork.

 

That's only because so many people cling onto this 3k rule. It doesn't mean those people wouldn't have gotten the same success using 6k oil changes. Oils have gotten better since the 70s, so why do people continue to hang onto the same oil change interval provided from that era?

I know many people who have been doing longer oil change intervals with synthetics with great success too. One person in particular has done 15k oil changes with his Toyota Landcruisers for about 15-20 years now. He got over 250k out of two of them. He now has a Z06 Corvette and is doing the same 15k intervals. It can be done, and it has been done by many people. Amsoil users have done long intervals for 25+ years with great success too. A good synthetic combined with a good running engine/good air filter simply does not need to be changed every 3k, and that's a fact proven through oil analysis.

 

Wow... That is the most interesting statement. Did you ever come to think that when an engine heats up its components expand which directly takes up those vast LT1 clearances? Now, what I want to know is... if you changed from your lighter weight oil which is thinning itself out to properly give protection in those clearance challenged areas due to the the prominent thermal expansion of the metal, how is your thicker oil going to get in there? Truth is... it doesn't.

Is your Mobil1 really getting to temps of 250 degrees? Maybe if you changed to a REAL racing oil like Royal Purple, you wouldn't see oil temps so astronomically high. You might see temps around 195-200 on a 95+ degree day with 100 percent humidity. What is your climate like? If its a 100% humidity day and the track temps are 95 degrees outside but 120 on the track, your actual thermal temp that the engine coolers are seeing are 192 degrees. I would call that pretty darn good oil to stay within 5 degrees of its ambient thermal efficiency. Unfortunately we get hot humid days like that in Texas.

Using a thicker oil is just wasteful. It wastes energy in the loss of performance for having to churn through a heavier viscosity and it wastes gas, period. I will agree that 3000 mile intervals with a performance synthetic are a bit extreme but to each his own habits. If you need a 1000 mile intervals to get some time away from the wife, by all means enjoy it.

So... would you mind devulging this "Oil Expert" who creates specialty oils for racing teams? Does he have a cart with Snake Oyl on the side of it? I am sure with IRL, CART, and NASCAR's mandatory lubricant submission testing he cannot be working in any really serious venue. Even the Formula Renault series has a spec oil with mandatory testing and impounds. What oil would he recommend for a Marine engine? They have the same tolerances as a LT1. Come to think of it... so do the Northstar and Cadillac engines. I cannot remember the last time I saw Grandpa doing a smoky burnout when leaving the retirement home for all the ladies to see. But, I would bet that when he has Johnny change his oil, he sticks with what the manufacturer suggests.

Hey... not to say that the manufacturer is always right. BMW sure made a huge F-up when they suggested we use Mobil1 5/30 oil in the M3. It took me $23K and an attorney before BMW finally made a recall on the M3 and gave all M3 owners a free change to the Castrol 5W60 oil.

You just have to understand that just because an oil is thin, it doesn't mean its not doing its job. It means it is. What is not acceptible is hydraulic breakdown and what Mobil1 is famous for.

 

Want more proof....my brother is a airline mechanic....he said they use Amsoil in the jet engines and NEVER change it...only add to and change filters. I guess it gets replaced when the engines are taken out for rebiulds at mandated intervals ever how many hours that is.

Speaking of hours...isnt that a better way to determine when to change oil....I think Ill rig up a timer and see how many hours it takes for me to get 3000 miles on my car...most of mine are highway going to and from race/show/club events.

 

Greg... that would be great and it is true to a degree. I am a Aviation tech and builder. What they do is fill the oil, but due to FAA mandated inspections of aircraft used for flight for hire operations they are required to replace the oil during their Progressive inspection or at ever 100 hour intervals.

But here is the part that will blow most people away... the reservoir that most large GE731 fans go in... mostly 737 aircraft and such. Their oil fluid capacity is not much larger than our cars.

 

I just had a rebuilt on my engine, spun rod bearing. The mechanic who did a rebuilt clearanced my crank for more performance, put all forged internals and told to use 15w-40 oil, which he said is the best for SB chevy engines.