Suggested drain interval

Patman

Staff member
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Oakville, Ontario
On your first interval with this oil you might want to run it to about 4k and have an analysis done just the one time so you can get an idea of how it will be. If your engine is clean you should have no problem with a 4-5k interval with any SL oil.
 
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3,320
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Bolivia
Right on Patman, but I wouldn't bother with the analysis til the second change. The first one always has residual oil and perhaps other gunk, depending on your previous oil.
 

Patman

Staff member
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Oakville, Ontario
Good point! The best way to determine the drain interval with any particular oil would be to check it more than once, or if only once, check it on the second interval at the earliest. I had not thought of that, but it makes total sense. This is also why when I switch to Schaeffers I won't do the full extended intervals all at once, but start out at 6000km first, then go about 8-10,000km on the second interval, and at that point I'll see if I'm comfortable enough to go 15,000km or not. It also helps in my case that I just did Auto-rx, and will only have one 6000km interval with Maxlife and then it's on to Schaeffers. So I'm starting out with a clean engine.
 
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330
Location
USA
Based on many of the positive comments I have heard about Chevron's Supreme SL oil I'm going to start using the 10W30 grade in my '99 Crown Vic. Police Interceptor. With the exception of my truck, I have never done much oil analysis. I generally run about 3-4K intervals with Dino oil and 5K with synthetic. I understand the comments about running oil longer. What is a safe interval to run the Chevron Supreme 10W30 in the Crown Vic? I'm not too crazy about spending $6 for oil and $3 for a filter ($9 for the oil change) and then $25 for oil analysis. If I have to do that I might as well change it every 3K. Any ideas on a good way to approach a reasonable interval??? My Ford manual states every 3K for severe service and 5K for severe service. I tend to do a lot of stop and go and idling so I usually stick with the 3K interval.
 

Patman

Staff member
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Oakville, Ontario
quote:
Originally posted by GROUCHO MARX: Er, I think the poster indicated he didn't want to spend money to have his used oil analyzed. [freaknout]
If he doesn't do at least one analysis though, he will never know for sure if he's chosen the right interval.
 
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3,683
Location
Chattanooga, TN
The correct interval (which by the way I don't believe anyone has defined what a proper change interval is)will change throughout the life of the engine based upon climate, driving conditions etc. So assuming that analysis is expensive compared to the cost of a do it youself oil change then a 3-5000 change interval will probably protect that engine for as long as he wants to keep it. There is a lot to be said for not doing analysis especially when the cost is compared to another oil change. Is the correct interval when the oil has lost its ability to protect the engine (ie: what does that mean (protect the engine) and what specific factors determine that) or is it at some point before the oil has lost effectiveness. Wear is inevitable, how much wear is the owner willing to accept? [ August 05, 2002, 07:31 AM: Message edited by: Spector ]
 

Al

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19,163
Location
Elizabethtown, Pa
quote:
Originally posted by Spector: The correct interval (which by the way I don't believe anyone has defined what a proper change interval is)will change throughout the life of the engine based upon climate, driving conditions etc. So assuming that analysis is expensive compared to the cost of a do it youself oil change then a 3-5000 change interval will probably protect that engine for as long as he wants to keep it. There is a lot to be said for not doing analysis especially when the cost is compared to another oil change. Is the correct interval when the oil has lost its ability to protect the engine (ie: what does that mean (protect the engine) and what specific factors determine that) or is it at some point before the oil has lost effectiveness. Wear is inevitable, how much wear is the owner willing to accept?
And if your analysis gives high numbers what do they really mean and what can you do about it? [Confused] I read a test once where Mobil tested their oil over a period of 6 years without a change. The irons went up over 600 and when the engine teardown was done, they were not able to find the source of the iron. [freaknout]
 
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330
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USA
I think that to get meaningful results (and this is just my opinion) from oil analysis, one needs to do a trend of several oil analysis results in sequence using the same oil. If I'm going to do this three or four times in a row it doesn't make sense since the oil changes are so cheap. If I spend $100 on analysis I can do 11 oil changes. I may just do one or two just to see what the results look like. Ultimately, I would like to do 5K changes if the oil is up to the task (or more if the oil was up to the task). The car is a '99 with 86K. I just recently came off active duty as a state police pursuit vehicle. The state did oil changes every 3K (they don't account for hours -- I'm sure it had lots of idle time). The motor looks spotless when looking in the valve cover with a flashlight and inspection mirror. I recently ran Valvoline All-climate SL rated (was on the shelf in the garage) for 1K miles. I changed the filter, added a bottle of Amsoil engine flush, ran at high idle for 20 minutes. The oil darkened a bit from the flush but it was not by any means nasty. I then immediately changed the filter, drained the oil and refilled with Chevron Supreme 10W30. I also installed a Super Plug magnetic drain plug. The stock drain plug threads were getting worn from somebody over torquing the plug.
 
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485
Location
Montgomery, AL
Of course, most people don't do oil analysis I just did my first one in July. I think one or two will give you some piece of mind. If you go 5K or 6K on Dino and the analysis looks good, you will feel good about keeping that interval. you will also save the cost of that one analysis in 3 oil changes. [Cheers!]
 

geo

Messages
62
Location
USA
ssmkn, Any OTS SL motor oil should be fine for 3-4000 miles as long as your car is good condition. Havoline/Chevron and Pennzoil appear to use Group II+ base oil in their dino oils. Unfortunately, OTS oils are reformulated relatively often, and oil analysis of a fresh sample pertains only to that sample. I've personally seen fresh oil analysis results change three times during the course of a year. This change includes the detergent and wear components. I no longer trust that the oil I place in my car today is the same oil and additive package that was tested 6 months ago. My opinion is that the oil analysis section of the forum is not conclusive and should not be used to determine your own drain interval. As an example, I've seen oil analysis reports from an 95 Chevy Surburban 350 and a 2001 Audi V6 with the same dino oil. The oil in the Chevy was used for 4400 miles. The oil in the Audi was used for 6700 miles. The analysis showed that the Audi oil was fine (and could go to 7500 miles) but the Chevy oil was excessively oxidized. Although the oil used in both vehicles was the same oil and operating conditions were similar, the numbers were very different. [Patriot]
 

geo

Messages
62
Location
USA
quote:
Originally posted by widman: An analysis helps understand what is happening and helps you - if you want to - fine tune your changes to your habits.
Agreed! [Smile] The key words here are "YOU" and "YOUR". [ August 05, 2002, 05:56 PM: Message edited by: geo ]
 
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