How often should I change oil?

[Rhett]

In the past, I have sent my oil off to Blackstone Labs and Oil Analyzers, Inc. for oil analysis. Oil analysis told me that my oil was fine after 3000 miles. So now I go 5000+ miles. I have gradually increased the oil change interval. Right now I'm at about 7000 miles and I am going to change soon and send off a sample for analysis to see how the oil is doing. I run AMSOIL.

 

[aldive]

Speaking of synthetic oil, my oil change place when I asked for synthetic oil, early in the X's life, they installed Castrol Syntec. I see a lot of folks here talk about Mobil 1. Is there a REAL difference between the two? If so, do I need to switch to Mobil 1? I have received very good results with the Catrol Syntec and have run it exclusively in the vehicle since new....well when I got to 15,000 miles I switched to synthetic, and now have 50,000 miles on the clock. If there is a benefit using the Mobil, I will switch. Thanks.

Syntec is a quality oil as is Mobil 1; doubtful you would find any significant difference in the two, however, only an oil analysis would show you that.

I used to use Mobil 1 and made the switch to Amsoil Series 2000 0 w 30 oil and did achieve an increase in mileage after the switch. Further, oil analysis data proves the effectiveness of the Amsoil oil during extended OCI.

 

[aldive]

In the past, I have sent my oil off to Blackstone Labs and Oil Analyzers, Inc. for oil analysis. Oil analysis told me that my oil was fine after 3000 miles. So now I go 5000+ miles. I have gradually increased the oil change interval. Right now I'm at about 7000 miles and I am going to change soon and send off a sample for analysis to see how the oil is doing. I run AMSOIL.

You are definately approaching the OCI delema in the proper manner. You will probably see that you can run the Amsoil up to 20 k miles with good results.

 

[aldive]

My owners manual says 7500 mi between oil changes I think. That seems way too long. If I change at 3000, am I just wasting oil? Also, are the new synthetics really better?

The proper way to determine if you are wasting the oil at that short OCI, have an oil analysis performed.

Are synthetics better? The answer to that question is a resounding YES.

 

[aldive]

Personally, all the synthetics/blends/high mileage oils are wastes of money in an engine designed for regular oil.

What do you base that rather bold assessment upon?

 

[aldive]

IMHO on a daily driver synthetic oil has no added benifits. There are others that don't share this opinnion and I'm sure they'll tell you, but I have seen engines last just as long on dino oil as they do on synthetic.

There is more value to synthetic lubricants than just longivity of the motor/tranny/rear end. etc.

 

[aldive]

I Would I benefit at all from synthetic? Would a blend work better? Or should I just stick to regular?

I too am a firm believer in the value of synthetic lubricants. The synthetic blends, in my assessment, are no better than dino oil; the amount of synthetic oil in a blend is very small and varies from manufacturer to manufacturer.

 

[aldive]

I never got it tested, but the oil is always dirty and stinks so that's reason enough for me to change it.

That might be a very Vlad reason for changing your underbritches, but not for oil.

 

[huskyfan23]

Ha! Very true. After actually thinking about it changing your oil every 3 months isn't really needed. I don't drive 3000 miles in 3 months and just sitting there isn't going to affect the oil. Maybe I'll start changing every 5 or 6 months.

 

[Interstate]

Suppose I'm thinking of switching to synthetic. Is there a special filter for synthetic? Is there a good weight for regular use and conditions like I said before? (I'll get it switched at the local zip lube)

 

[aldive]

Suppose I'm thinking of switching to synthetic. Is there a special filter for synthetic? Is there a good weight for regular use and conditions like I said before? (I'll get it switched at the local zip lube)

No special filter needed; however, its wise touse a very good one like Mobil 1 or K & N.

5 w 30 is good.

 

[jayhawkexplorer]

What do you base that rather bold assessment upon?

I'd base it on the vehicles (listed below) my family has owned during my lifetime. All of these vehicles have run on Pennzoil/Quaker State/Castrol dino oil and a Motorcraft or Fram filter. All have gone well past 150,000 miles with not one engine problem from any of the cars. And I'm convinced that a regular oil change interval was one of the reasons that all these vehicles lasted so long with no problems. I don't see what benefit synthetic oil would have made in any of these vehicles. Maybe a small mileage increase, but the cost of a synthetic oil change (3x that of a dino oil one) would offset any of the benefits. I realize that an extended interval may have been a benefit, but personally taking 15 minutes to do an oil change every 3,000 miles isn't that big a deal.

Like I said earlier in the thread, synthetics are great but I don't see the point in using them in a vehicle not requiring it. If I drove a BMW, Porsche, Viper, etc. that requires Mobil 1, I might bother but until then I don't see the point.

It will be interesting, however, Adlive, to see how long your Explorer lasts with all the money you've invested in Amsoil fluids and other mods. If the dang thing goes 500,000 miles with no rebuild necessary, I'll declare myself wrong Cheers.

'77 Ramcharger 318
'84 Accord wagon
'88 Taurus 3.0
'92 Tempo 3.0
'96 Aerostar 4.0
'96 Camry 3.0
'98 Windstar 3.8

 

[Bill Kemp]

I sure dont think Ford and most all other car co.s would recoment 7,000 or so between oil changes if it were detremintal to your engine.
Years ago when oil was not near as good as it is now, and neither were engines, 3000 miles was probably OK. Today all your doing is useing more oil. The benefits are realized by the oil companies and the quick change oil places.

 

[jayhawkexplorer]

I sure dont think Ford and most all other car co.s would recoment 7,000 or so between oil changes if it were detremintal to your engine.
Years ago when oil was not near as good as it is now, and neither were engines, 3000 miles was probably OK. Today all your doing is useing more oil. The benefits are realized by the oil companies and the quick change oil places.

I would have to respectfully disagree 100% with that Bill. Check out this editorial from Car & Driver's editor, it appeared in the magazine last month. http://www.caranddriver.com/article.asp?section_id=27&article_id=8794&page_number=1
It seems that Volkswagen/Audi, Chrysler, and Toyota have all had major problems with oil sludge in the engine brought on by the extended oil change intervals they had recommended on their newest vehicles. Major warranty costs were absorbed by the companies, and they had to write their owners to change the recommended interval for oil changes. I'll stick to 3 months/3,000 miles.

 

[aldive]

Sounds more like engine design problem to me.

 

[jayhawkexplorer]

Sounds more like engine design problem to me.

I would seriously doubt that any of those companies, especially Toyota, has engine design problems. Toyota's 4 cylinder engines are some of the most reliable, durable, well designed engines ever made, and those are some of the engines that had the sludging problem.

 

[aldive]

If it were an oil problem, why would it not show up in Ford engines?

 

[jayhawkexplorer]

Dang it Adlive. You win I don't have a good response to that one. Interesting to think about though.

 

[Bill Kemp]

I stand behind my statement. Doing what the mfg. recomends, according to the C&D article would have prevented the sludging. The cars were determined to fall into the "Severe Use" catagory and the oil was not changed according to that schedual.

 

[Glacier991]

I am going to put my toe in these waters carefully. Let me start by saying I have an airplane with some other guys and we test the oil (do oil analysis) periodically but change it every 50 hours as per the spec, regardless. (We test for the usual things but look carefully at metals.)

On my cars I buy decent oil by the case when it is inexpensive. I run mainly Motorcraft filters. I change the oil every 3000 miles (ok ok ..3000 to 4000 I am not THAT ****) even on the 23 year old Mercedes Diesel. I change filters every oil change but skip it if I feel like changing oil and don't have one handy. (now and then thing to skip in other words - except for the Diesel). I know the stuff about lubricity, antifoamers, cross chaining polymers etc... but in the end my thought is that dino oil is cheap, and there is acid and stuff in that oil after a while. (e.g. I can test it and tell you my hot tub water is clean and safe, but if I toss it and refill, the new water is just a heck of a lot better looking and feeling).. anyway...By the time I pay for full syn and do an oil analysis, I have a few dino oil changes bought and paid for. (Don't get me wrong an oil anaylsis is an awesome tool... we caught a bearing going (bronze went off the chart) in a high time Lycoming aircraft engine with it)...anyway, I run full Syn in winter... reg dino in summer...

So that's me, whopee. big deal. No one here has the ultimate high ground in my view. (Though I highly respect what Aldive says on a variety of issues). If you want the 500,000 mile car, install a pre-oiler pump and stop worrying so much about oil per se. Most wear occurs on dry startup. Thar's the rub, as they say. (IMHO). (And why I run full syn in cold weather - it oils faster).

I'm just too lazy to find the "outer limits" of oil life I guess.

(Altho my Ex has 210K and a cylinder leak down test that will make you smile. And if I had a bad cylinder I'd lay you 5 to 1 it was a valve before the rings)

ps. If you have a VW bus, that engine is notorious for catastrophic main bearing failure after about 150,000 miles... testing oil in that engine every 10,000 miles above 150,000 might save your bacon.... maybe a thread about oil testing would be a good place to leave this debate about how often and enlighten about what we can learn from old oil).