Question about synthetic lubricants....

[Robert1994]

Based on the recomendations of this board, I have
been running Mobil 1 in my car, and will change it
at 3,000 miles.
I have a 2000 Toyota Tacoma with a supercharger. On
the recomendation of several racers in my area, I have
run Synergy synthetic oil in my truck since the first
oil change. The shop that I take the truck to for oil
changes (easier than recycling your own oil) says that I
need only to change the oil filter every 3000 miles, but
NOT the oil, until it appears dirty. I have over 40,000
miles on the truck now, and the oil looks brand new.
The shop doesn't make any money when they don't sell me oil,
so I can't see any motive for him to tell me this.
Why would the Mobil 1 need to be changed every 3,000 miles
yet the Synergy oil does not ????

 

[Steve 00RT/10]

There is no reason to change Mobil 1 at 3000 miles unless you are racing the car. It is the personal preference of many here to change it frequently just because the car is a Viper and oil is cheap insurance. If you use a good grade of filter--one specifically designed to filter synthetics--(Mobil is good),that wouldn't have to be changed at 3000 either, unless you were driving in extremely dusty or dirty conditions. You could prove this point by taking an oil sample at 3000 miles and sending it in for an oil analysis. Your truck garage could probably steer you towards an oil testing lab. If I remember, the owners manual says 6 or 7000 miles with Mobil 1 in the crankcase and normal driving.

Steve

 

[Tom F&L GoR]

Unlike gear oil and transmission fluids, engine oil has a constant introduction of highly acidic exhaust blowby, water (vapor from the combustion process), dust (whatever gets by the filter, and quick temperature fluctuations (that attempt to cook or condense materials) that make it's useful life less predictable.

I can tell you that if the oil "looks" good visually for a long time it is a crummy oil, since part of the job is to pick up and suspend deposit-forming material. In fact, the quicker the oil turns dark, the more it's "cleaning" and the better job it's doing. All that "stuff" is then flushed out when you change the oil.

If you could absolutely predetermine what will use up the oil quickest you could alter your oil drian strategy appropriately, i.e. if high temperature, then many would advocate a synthetic; if it's overall robustness, then many would advocate a diesel oil, if it's dust and dirt, then many would advocate the filter change.

It's like taking a shower- what's your personal hygiene preference and what you were doing beforehand...

This is getting a little dated, but here's some general info:
oil info

 

[GTS Dean]

I have been running very extended Mobil 1 15W-50 drain intervals on my GTS. I have oil sample analysis done about every 3 to 6 months. When the reports come back with fuel dilution, then I change it. When tracking the car, I usually add a quart or so of makeup oil each weekend. 2/3 is probably lost to combustion, the balance is leaking or puking out the valve cover breathers. I tried the Mobil 1 Delvac diesel oil in it per Tom's suggestion, but it wouldn't seem to stay in the motor. Seems like I used double the amount of makeup oil during that period.

I ran Exxon SuperFlo 20W-50 (non-synthetic) in my '93 RT-10, but changed it every 2500 miles. It didn't use any oil at all and the engine stayed dry as a bone. I used Exxon because it was free - we go through about 4 or 5 tanker truck loads of engine oil every year in my company - not to mention hydraulic, transmission and differential/final drive lubes.

 

[99 R/T 10]

Tom makes good points on the oil, but what about the filter? I think most peopl on this board use the Mobil 1 filter and for good reason. Check out this site. Although it's hasn't been updated in a while, it still has some good info on the filters that are out there and the conclusion para. says

"If money is no object, I would go with the Mobil 1. Although it has Champion internals, it has a really tough synthetic fiber filter element, which is the Champion’s only major downfall. The element is stronger and thicker than the Purolator, but they claim that it flows just as good as paper. As with the other low-end Wix filters, it has no internal sealing problems. The $10 price tag is a bit steep, but it is the best filter you can buy retail. Watch for “Mobil 1 Oil Change” sales, which includes 5 quarts of Mobil 1 synthetic oil and a Mobil 1 filter. Granted, there are probably better filters available through mail order, but I haven't tested those yet... "
http://www.scuderiaciriani.com/rx7/oil_filter_study/

 

[grayman]

Money should not be an option when changing the oil. Exhaust blowby will increase the acidity of your oil regardless of what type you run. Changing the oil at 3k miles is about as cheap of insurance as you can possibly get, so dont cheap out on your $60000 investment to save a couple dollars of oil.

 

[JonB]

Anyone running K+N, (ACR-MoPar) or SOB "Hi Flow" air filters should consider their motor to be on an "extreme service" schedule and change oil at 3000 miles or less........

Like Tom says, dust, pollen and abrasive microscopic debris gets past air filters. More dust gets past HF filters. Even more dust gets past un-oiled / neglected HF filters. {buy TWO sets and rotate them after CAREFUL reoiling that ensures tackiness.)

 

[Bill/APEX Motorsports]

Oil is CHEAP. Engine wear is NOT!

We recommend 3k-4k mile oil changes, even with the excellent Amsoil synthetic oil and filters we use. If you opentrack the car, it doesn't hurt to change the oil/filter after every hard event. Better safe than sorry...

 

[GTS Dean]

I've got over 18k on the odometer. I asked the tech to pull a couple of rod caps and one main cap last time the pan was off to see what things looked like. No probs.

 

[Janni]

Since Dean is doing regular oil analysis, he is monitoring his oil's ability to filter out the contaminants generated by the engine. Therefore, it is perfectly safe to change the oil when certain indicators say the oil is no longer up to the job. The OTR / truck / heavy equipment folks do this all the time - since their vehicles consume a lot more oil, and time spent in the shop for too frequent oil changes means lost revenue. At the same time, so does a broken down truck, so oil analysis is the most economically efficient method of maintenance.

3K miles, or, as has been recommended, hours and RPMs along with how severe driving conditions are, is the way to do it without oil analysis.

Bottom line if you are monitoring the oil's ability to do its job (i.e. analysis) then you change it when it tells you to - regardless of miles. If you don't monitor, you change it as often as you think you should - and the more the better - so you NEVER exceed its ability to filter / suspend the bad stuff.

 

[JonB]

Rule Of Thumb:

100 Track miles = 1000 Street Miles.

Can work for trans/diff too, but in reality change sooner!