I agree with that completely. As a licenced technician, on gasoline engines I tend to stick with the 3000 mile OCI (including my own), unless the oil has been analyzed, or the miles are completely highway at operating temperature with no short trips. Every week, i can look at a car and see droplets of condensation dripping off the underside of the oil cap and or a buildup of milkshake like substance in the same place, from short trips with insufficient engine warmup. Even with the modern oils of today, one can still determine neglect by removing a valve cover or timing cover. The dark crusty scale covering the inside of the engine still shows lack of oil changes, just like the engines in the 1970s did.

It's much safer and easier to stick with a familiar, consistent interval, than to try to put it off for an extra thousand miles because you don't remember any short trips to the store since the last service.

 

I don't mind disagreement.

I would ask you to clarify your comment, though: "The oil today has been reduced in it's lubricity capability".

I'd ask: "compared to what?"

I think many would agree that SM specs aren't as good an oil as SL, and I think we almost all agree that CI diesel oils are better than CJ specs.

But the ASE recommendations go MUCH farther back into history, as I mentioned, to a an ancient API spec that was far inferior to even an SM oil, never mind an SL. We're talking about over 30 years of oil improvement, and 30 years of no change in recommended OCI of 3K miles.

The hilarious irony is that emissions considerations may end up producing an oil so inferior that we end up coming full circle and a 3K OCI is perfectly valid.

 

As a retired (from the business) ASE master tech, all I can say is what the heck do they have to do with when you change your oil? Read your manual.

 

As an A.S.E Master Certified Tech myself, I change the oil in my 99 Caravan every 2,000 miles! Well.....that's what the sticker shows at least! Sometimes it takes the wife a couple of hundred more to tell me it's due! I change it in my truck every 5,000 miles. Overkill? Maybe! Waste of money? Maybe! I feel confident in knowing that I am going to extend the life of my vehicles by maintaining the vehicle to the best I possibly can. I change the trans fluid every 35K on both of them as well. It is the cheapest and easiest thing you can do to extend the life of your vehicle. That being said, IF A.S.E. wanted more "business" for technicians , they should advise longer service intervals! That would almost ensure more work in the long run! The one thing I can remember from my talks with a Chrysler engineer is his comment about the Schedule A and Schedule B service intervals. Schedule A was only introduced because of the "cost of maintenance" ratings by JD Power and the sorts. ALL manufacturers have followed suit, and really........have you ever read the Schedule A ? No extended idling, no stop and go driving, no extended highway speeds, no dusty conditions, no temperatures below 32*, no temperatures above 90*, ect, ect..........WHO DRIVES LIKE THAT? NO ONE! So , after my long winded sermon, I would have to agree with A.S.E. as for the majority of the drivers on the road, 3 month 3,000 mile oil change intervals should be the standard for those that pay someone else to do their service work. For those that do their own maintenance, they should be competent enough to figure out what schedule fits their needs.

 

I think that if ASE wants to maintain credibility, they should be suggesting something that is gonna help the consumer. Saying 2k intervals may help increase engine life, but the oil will have plenty of life left in it. Waste of money. Tell them to go 10k intervals so they will have failures to drum up business is pretty underhanded, and I'd stay away from who ever told me something to harm my vehicle. Give the facts, and build your case on that. Anything else is just self serving propaganda.

 

That's a new one to me... can you tell me where you found that out?

They only changed my wifes BMW every 12 or 15,000 miles.... and I couldn't stand it so I changed it between on my own.

 

I am a BMW tech, its true but its on later model cars. If the vehicle doesnt say you need an oil change you dont. No need to distrust it. 15K on a BMW is normal for some driving conditions. They are now designed to go that long. Just take care of it when the car tells you too.

 

My philosophy as well! Cheap Insurance! I'm guessing the original comments about ASE mechanics vetoing extended oil change intervals may be a response to the new SM rated oils?

I use a very high grade oil (still CI-4) and change every 7500 miles in the winter and @ 5,000 when racing in the summer. Would I still do so, if I wasn't getting a discount........ you bet!

I thought most of those "time to change oil" dash lights went strictly on mileage....no? BMW's.... maybe not.
RJ

 

Exactly where did you get this information - cite it please.

 

No they don't work strictly on mileage, GM for instance uses quite a few pcm inputs and a complicated algorithym based on engine run time, average speed, idle time, average engine temp., mileage, fuel useage, throttle inputs, and more that i can't remember to determine the OCI. It tailors your OCI based on your particular driving style and conditions. I think it also used ambient air temp in the calculations. It works too, vehicle that were used in "extreme" duty applications with lots of towing and extended idle time had shortened OCI's, and the old man cars that were used lightly had extended OCI's.

 

High pressure lubricants such as zinc dialkyl dithio phosphate - aka ZDDP - manganese, and? ( RJ, help me out here!) have been removed from some engine oils because of their adverse effects on gasser catalytic converters, but diesel catalysts are chemically different, so diesel-spec oil still has high levels of ZDDP.

 

Sorry, Not accurate! Diesel uses same ZDDP (you got it right) & same Phosphorous additives... just more of it. Both have been reduced in percentage by weight.
Based on Oil Analysis I have seen, for normal driving (no excessive towing) we are good with the new CJ-4 oils for 5,000 miles oil changes. But the CI-4 is still preferred if you can find it.

RJ

 

Sure - I was comparing gasoline-spec (which I understand has most or all of the ZDDP removed) engine oil to diesel-spec oil; however, what do you think of (Shell's OEM Technical Service Manager) Stede Granger's statement:

The exhaust catalyst found on diesel engines isn't the same as that of a typical passenger-car application, so we're able to retain high ZDDP levels. The API specification change to CJ-4 for 2007 has resulted in moderate zinc reduction from about 1,400 ppm to 1,200 ppm. And even at these slightly decreased levels, ROTELLA T 15W-40 conventional and 5W-40 synthetic still contain three to five times the amount of the desirable anti-wear additives as some current gasoline-engine oils.

 

Sales Hype.
Never should have been as low as 1400 ppm in the first place.
But the CJ-4 is down around 1200 ppm..... I believe that is the EPA, 2007 guideline (off top of my head).

Our CI-4 oil starts out, in a diesel engine, at 2200 ppm Min.

RJ

 

So Rotella T didn't have a reduction of ZDDP from 1400-1200ppm as Stede stated? If it's a factual error, I need to get the magazine to print a correction... whether it was a misquote, typo or corporate BS.

RJ, do you have any good links for the additive breakdown for oils such as Delvac, Delo 400 or Rotella T ? Or is that all proprietary info?