Case For The 3,000 Mile Oil Change

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Originally Posted By: JAG
Direct injected gas engines also increase fuel dilution relative to port-injected ones because some of the liquid-phase gasoline hits the cylinder walls before vaporizing.
Part of the great advantage of DI engines was that the piston ring crevices are filled with air only rather than air/fuel mix (even vaporised fuel), in an area in which the quench is such that flame propogation is denied. Crevices release their unburned fuel during the expansion stroke, increasing HC emissions. For raw fuel to be hitting the cylinder walls is an epic fail for the engine designer in a gas fueled engine IMO. Even simply from a wall washing perspective.
Originally Posted By: Bluestream
Do you have the link that states: "GMInsideNews that technicians believe that extended oil change intervals were partially to blame." I don't see how dirty oil can cause a chain to stretch; Sounds like they're passing the buck due to poor design or poor quality parts...
(IMO again), it's a design issue. My Nissan ZD30 engine is a DI diesel, DOHC, 4 valve per cylinder design, which Nissan expressly states no more than CF-4 rated oil, pushing us owners into PCMO territory to avoid warranty issues. There's an argument used by Nissan (and seconded by oil company techs) that a dispersive oil means more, smaller abrasive particles in suspension, which Nissan have found leads to more top end and cam chain wear. They want a less dispersive oil that will hopefully be filtered, or drop out somewhere else (?) A big part of the issue (once again, IMO) is that to get the valve included angle low enough for a direct injection diesel, that the cams have to be very close together, to get the valves flat. I've seen a head off one, and the valves are all but flat. This means that the cam gears have to be very small, so they don't run into each other. Which sends the chain tension through the roof, as the torque required to turn a cam needs to be provided by a shorter lever arm, and therefore more chain tension. Greater link loading, greater wear, and greater stretch. More particles in the interface, more still.
Since I run syn oil in my cars I think 3,000 is a waste. I go 5,000 to 7500 miles. For some running dino in truly harsh conditions 3,000 may be warranted. I think the 3,000 mile would have an advantage in possibly catching a issue earlier or helping make sure that other fluids including oil are checked and kept filled.
To catch an issue early would imply that there's some sort of testing for the issue. A Jiffy Stiff isn't going to pick up nearly everything that they might see, and no-one will do a UOA at 3k miles to see what might be taking place.
Of course, at 3-5k oci there obviously wouldn't be any lubrication-related failures, so there would be no need for those UOAs. But it's not like your UOA has to match your oci. You can still do UOAs every 10k-20k miles for the other benefit of the UOA (make sure coolant seals, filters, etc aren't leaking, nothing broken and throwing huge wear numbers, etc). It's pretty much what I do (3-5k oci, 15-20k UOA) since I have a sludger.
My Mazda calls for 5k intervals for severe conditions and that's what I've been doing while under warranty. Now I'm doing 6.2k (10k KM) OCI's on PP, I'm not worried. Plus, I would not trust quick lube places to perform necessary inspections, these guys operate at fast turn around, so shortening OCI's will not ensure that other items are looked at, cars would still have underinflated tires, be low on oil, coolant etc. even if we changed to 1k OCI's because majority of people are clueless. It's a catch 22, clueless people rely on others to maintain their cars, so they think that when they bring their car for an oil change, everything will be checked then, quick lube places know that majority of their customers are clueless and will not bother checking their work, so they don't do it.
Originally Posted By: Drew99GT
I'm surprised GM didn't start recommending 1,000 mile OCIs to cover up the I/M gasket problems!
Thats funny!!
Originally Posted By: ZZman
I think the 3,000 mile would have an advantage in possibly catching a issue earlier or helping make sure that other fluids including oil are checked and kept filled.
Exactly. That's my take on it too. Personally, when I take my vehicle into a quick lube (WM TLE for the most part) I tell them to adjust the Oil Change sticker to + 6000 :) Current ODO + 6000 and input that on their typewriter machine :) cause yea, no need to change oil at 3k....but for those people who don't like airing their tires, checking their trans fluid, brake fluid, air pressure, tire tread, etc; that's who the quick lubes are selling to wink Personally, when I take mine in, I tell them to not touch my fluids at, they tend to just water-down my washer fluid.... I got a friend who works there and he says they got a huge tank, and they add a 2 packages of green washer additive to the tank, but by the time it mixes in the tank, it's no longer green when it goes in the washer reservoir :)
Recently my work changed from a 1500 to a 3000 mi OCI of who-know-what 5-20. Most of out fleet are F350s with 5.4 motors, overloaded tooboxes, towing frequently, very urban stop and go, and extensive idling. (My truck weighs in at 9500#.) Most of the trucks are 2004s or 2005s, and most have about 50,000 miles. I was just reassigned a truck last week that has 2700 miles on the oil. It was 3 qts low! While it looks ok on the stick, it's obviously being beaten up by the awful things we do to the truck.
I think a lot of people here miss a big point and that is the 3k mile rule is just an arbitrary number. It means <span style="font-style: italic">nothing</span>. In order to determine an OCI, it depends on the engine type, OEM recommendations and oil type. Oils that are built with higher levels of additives/detergents etc. (Amsoil/M1 etc.) can withstand more time in the crankcase than a normal conventional oil. I stand by the 3k mile rule needing to die. Put it away and let the data suggest the UOA.
I agree with you. 5K is plenty short with a Grp III. I do 4K changes when using bought really cheap Grp II, which I only buy because it is cheap, although I know that it is also very good. 3K? For what possible reason in modern engines using reasonably recent spec oil? If a mass-market street car engine really needs 3K changes, it has some basic engineering, manufacturing or assembly problems.
Originally Posted By: ottotheclown
Ok, Ok, we must notify Chrysler, Ford, Nissan etc that suggest 3,000 oci with severe service that they are wrong. We have discovered this is a waste of oil and a myth. It is amazing they the engineeing dept. still go by what the quick lubes made do for all these years. Not to mention uncle Winifred, in Maine who has 345,000 on his AMC Gremlin, doing 12,000 oci with Mobil 1. I will sleep well tonite..
I think that sums it up. 3,000 mile oil changes might be a waste. Lots of people have shown they can go much further without ill effects. Back in the 1980s, we ran cabs for hundreds of thousands of city miles, with 6,000 mile OCIs, Wix filters, and QS, all during the peak of the QS sludge-bashing. They all held up quite well. That being said, if I were buying a used car, all other things being equal, I'd rather buy it from the guy who changes it religiously every 3,000 miles than from the guy who never pulled the dipstick. From the stories and the data here, we know perfectly well that good oil can last a lot longer than that. However, the average guy who lets his oil change go beyond 10,000 miles isn't the guy using a top oil, with a top filter, and doing UOAs. The average guy exceeding 10,000 miles simply doesn't give a [censored].
I have an '08 Mazdaspeed3 and do oil changes at 4,000 to 4,500 miles using PP 5w-30. This HTO-06 rated oil has held up very well and as the engine has aged ( at 40k now) it appears to be less hard on the oil (less gas sell in the freshly drained oil) . Overall, these are great cars with plenty frisky engines and good gas mileage to boot. I think the soot issues are due to an effort on Mazdas behalf to keep the turbo from melting off the car. There's always talk of joining the " zoom zoom BOOM" club but these are generally owners who have modded their car to the hilt; I just drive mine totally stock with zero problems so far. Maybe it's the PP....
Another issue with DI (besides fuel dilution) is that the gasoline doesn't spray across the intake valves and clean them. Perhaps this relates to the soot issue that JAG mentioned.
Whether some people want to face it or not, there is still a need for 3,000 mile OCIs in rare cases and it's turning out DI may be one of them. Contaminates are contaminates. The oil might have a ton of life left in it but if you have a bunch of [censored] floating around in there it still needs to be changed. Off topic but I flipped the visor down on my GN, never really paid attention to the oil recommendation but to my surprise it said 5w-30 for cold conditions, 10w-30 for warmer conditions and a 7,500 mile OCI on SF oil. The 7,500 on SF on a conventional in a turbo car is what really surprised me.
Originally Posted By: BuickGN
Off topic but I flipped the visor down on my GN, never really paid attention to the oil recommendation but to my surprise it said 5w-30 for cold conditions, 10w-30 for warmer conditions and a 7,500 mile OCI on SF oil. The 7,500 on SF on a conventional in a turbo car is what really surprised me.
I was cleaning up today and found an OM from a 1984 Ford E-150 I owned. Unleaded Fuel Normal Driving conditions oil and filter 1 year or 10,000 miles which ever comes first. [Synthetic oil not mentioned]. Unique Driving Conditions or Severe Service 3 months or 3,000 miles. API SF oil. They gave several options with a graph showing different grades of oil that could be used.
If you repeat a lie enough times in your head, soon you start to believe it. Old myths and internet garbage needs to die. In the video below, Peter Lord of Goodwrench explains "much tighter control of the fueling of the engine" as he stands next to new Chevrolet Malibu.
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