Do I really have to change my oil every year?

[Ronald L.]

Re: Do I really have to change my oil every year?

In one of my former lives, the General needed to get C.S. corrosion and supply base under control, that also included the plants in how they handled the engine coolants, I got tapped to take over 20 suppliers down to 6 based upon quantitative quality and that was pretty easy since some did not comply to the minimum specifications, and others though they were above the customer.

Short of having access to a analytical chem lab, there is no test I know of that will tell you if your system is in balance.

The pH is important indicator, more for a gross corrosive situation that is out of control. But what we do not have is a mechanics test that says you have so much of this left, so much of that, etc.

I know the ultimate is to drop those freeze plugs, but that is one thing I'm a little afraid to do once every so often and in my "opinion" not necessary if dealing with a relatively clean system free of solid crud in those same cooling jackets. If the engine has been tanked, restored, and the same for the heater core and radiator, then the simple and cheap insurance is to change this every year.

In simple terms, what is $30 of coolant and distilled water as compared to changing a heater core? Or the cost ($700) of a BB radiator???

[Duke W.]

Re: Do I really have to change my oil every year?

Those pH test strips were developed for obsolete IAT (green) antifreeze. They don't apply to Dexcool or other OAT formulations, and I'm not sure that they apply to HOATs like Zerex G-05.

Zerex G-05 should be okay for five years in a collector car that is not driven much, but there can be a problem if the car is very rarely driven. Because the coolant is not being circulated, local anti-corrosion additive concentration can be depleted and corrosion can occur. This typically occurs in nooks and crannies.

As far as oil is concerned, if the car is only driven a few hundred miles in a year, AND IF THE ENGINE IS FULLY WARMED UP WITH EVERY DRIVE - say at least 10 miles and 30 minutes of operation - the engine is in good condition with minimal blowby, and the car is kept inside in a non-condensing humidity environment, and you use C-category oil then it's probaby okay to go 1000 miles or two, maybe even three years, whichever occurs first.

It's a matter of understanding your driving and storage conditions, using the best available fluids and understanding how they deterirorate, and then applying reasonable judgment. It's ultimately a judgment call.

It's best to start and drive the car to full warmup - at least ten miles or 30 minutes of engine operation in mild weather - at least once a month, but if you store the car in the winter let it sleep with fresh or near-fresh fluids.

Duke

[Mike G.]

Re: Do I really have to change my oil every year?

i emailed mobile one and they said change it every year. they did not give a reason and i did ask why. i do it just to be safe. dont want to hurt a motor over 50 bucks.

[Duke W.]

Re: Do I really have to change my oil every year?

Mobil 1 is a poor choice for a vintage Corvette. If you own a late model Corvette, Mobil 1 is required for warranty coverage, but if you are off warranty, drive it no more than 5K miles per year, don't start it in subzero weather, and change it once a year, a conventional S-category 10W-30 is okay, but I'd probably use C-category 15W-40.

Duke

[Clem Z.]

Re: Do I really have to change my oil every year?

i emailed mobile one and they said change it every year. they did not give a reason and i did ask why. i do it just to be safe. dont want to hurt a motor over 50 bucks.

the car companies say change once a year,they warranty the engines so the oil companies can not say any difference. mobil 1 has records of engines like in new york cabs going 250,000 mile without a oil change,just filter changes. when i started using mobil 1 back in 1988 i ask and got a lot of info from them about when to change oil and they sent me the info on the 250,000 mile engines