I just had Blackstone do oil analysis on my Cobra and Jeep and always wondered about changing oil by duration in the engine (3mos, 3000miles etc.) I got my results back and was very surprised at the report. The Cobra hasn't had the oil changed in 7yrs and 753 miles. The Jeep was 1yr 4mos and 5083 miles. Here are the reports....
i always called BS on the 3 month thing....isnt it just sooo convenient to have it be 3 months and 3000 miles? lol that is pretty awesome though
Thanks for the info! Very informative. Still gonna change my oil every 3 months though because clean oil is better than dirty...oh and I have a service plan I have to make use of lol..
nice info!! thanks for sharing!!! i have always called bs on the 3/3,000 thing..... maybe with crappy traditiona oils, but synthetics i have routinely driven cars HARD for 5k - 7.5k between changes with zero issues!!! hell, my last bmw had 15K oil change intervals!!!
The 3 month part is for city drivers. Start the car run it 5 miles to work through stop-and-go rush hour traffic and shut it off. Naturally most of the blowby particulate happens when you first fire it up. The guy who does the 10 mile freeway commute is going to have cleaner oil after 3000 than the guy with the short city commute after 3 months. It was just a guideline for the peasant masses. "90% of engine wear occurs within the first 10 seconds of starting the car"
i have autostart on my truck....i always run my truck for at least 2 min's before i start moving.... does that actually help?
Why yes. (I think 1 min. is fine). The main reason for it is oil circulation. You shut it off while it's hot. Oil runs off all the surfaces and out of all the tubes and collects in the pan. and maybe a thinner coating than while it's running. It's cold when you start it so enything that contracts will have done so leaving larger clearances and tolerances. It takes just a bit for the oil pump to fill all the delivery channels and the gravity return routes. So you have a thinner layer of cold oil until it starts recirculating. You're still going to get most of your engine wear right after cold starting but it's going to be way better than turning the key and burning rubber out of the driveway. That's also why you want to keep the load minimal until it gets warmed up just a bit. This is not one of those huge things where you'll see a measurable difference next year but one of those things where a few years down the road it's going to be burning less oil and your engine should live longer in the end. If your girlfriend's husband is coming out the door with a gun, don't wait. Turn the key and floor it.
thats interesting dave, i was always told modern engines didnt need that warm up period and that it was best to start the car, put it in drive (or 1st) and drive at a low rpm for a bit to get the motor running at optimum.
Sure, cost wise and emissions. The amount of extra gas you burn and the emissions from letting it idle. The average person trades in their car how often? A very few of us keep our cars until they turn to dust. So the added engine wear doesn't really come into the picture. It's rather similar to the fact that you don't need a PCV catch can. and there is no reason to burn premium gas in modern cars. So if you do start and go, then driving at low rpm (and minimal load) for a while would alleviate a good part of it. But just letting it idle is going to be better. If you wanted to really go overboard you could use a block heater and a pre-oiler (electric oil pump you switch on for a few seconds before starting and then turn off). Besides, pulling out of the driveway and idling along for a few minutes doesn't work so well... all your neighbors who are behind you and late for work are going to be honking their horns and giving you the finger.
You did read the part about 7years and 753 miles? That is no lie and the report came back good. It's not like I drove a hundred miles all at once each year.
Well sure. For all intensive purposes synthetics don't have a shelf life relative to organic oil. So now it's going to be all engine hours and driving conditions. It doesn't really matter how long it sits still. And with today's oils and filters you could probably change 3000/3 to 7000/6. Basically the point is that you can wear out your oil with a lot fewer miles of stop-and-go city driving than way more freeway miles. First of all the conditions are harder on the engine/oil and secondly you are racking up a lot more engine hours per mile. If you changed oil based on engine hours there would still be a difference but it would be a lot less. It's also going to make a huge difference what shape your engine is in. Most people have a few miles on a less than meticulously cared for and driven engine. I'm guessing your Cobra doesn't burn much oil? Did you have to add a quart after than 735 miles? Did you turn the key and immediately head out into rush hour traffic? These rules of thumb and manufacturer recommendations have to cover the general masses. The assumption is that everyone drives their car every week day and maybe on the weekend. The average chump putting in less than 3000 in 3 months (or 7000 in 6 months) is likely to be doing very short commutes of stop-and-go driving. Oil wear is going to be sort of equivalent. So forget about the time sitting. 735 miles just isn't enough no matter how it was driven. Surely the best way to do it is with oil analysis like BlackStone and go by that but your average Joe isn't capable of that. So if you've got to come up with a rule that's going to work for the lowest common denominator that's what you end up with. I think JMatt has to change the oil in his camero about every 7 miles :grin:
yeah any car needs to have the oil come up to temp before you should be getting on it no? haha....thats why my commute is good...i can drive nice and slow through the streets where i live for about 2 miles....theeeeen i hit the highway :happy: haha
Oil and Filters are pretty cheap when you consider the price of a SRT-8 or SRT-10. Whats the point in saving a few bucks on cars like these. By the way the zinc content in whatever oil was being used is pretty high. Yes Zinc is used as a protection agent but it is really a short cut. I never run oils with high zinc content...
So it looks like the Royal Purple has an above average zinc content and the Mobil 1 is below the average. What oil do you usually use? Amsoil?
