oid change 3000 vs 5000 miles

[JUSTIN]

I have 3 cars to maintain. 65 riv, 93 truck, 95 van. I change the oil myself at 4000 miles . I have heard commercials say 3000 miles. The new cars recommend 5000. so what is optimal? I would love to go for 5000 miles and save me a little work and be easier to remember (whenever the odometer is a multiple of 5000). but not if its going to hurt anything.

[Guest John Chapman]

Justin,<P>Just my preferences, but on my old cars, I stick to 3000 miles or 90 days, because the engines aren't as tight and you get a lot more blow by contamination in the oil. Plus, they tend to sit a lot more.<P>I think on newer cars that are regularly driven, you can get by without problems by sticking to the manufacturer's recommendations, commonly 7500 miles for oil and filter now. The caveat to this is that interval is only for driving not characterized as 'severe'. When you read the hand book closely, you'll probably find that most of your driving is 'severe', but I still think you're OK at 5000 mile intervals.<P>Cheers,<BR>JMC

[Guest]

The quick change places and even the auto dealers would like you to change oil every week. They make good profits on this.Oil reserves in the earth are depleating fast.Millions of gal.per day could possibly be saved if we all followed the manufacters.advice on oil changes.I dont always wait for 7500 mi. myself,but close to it.I am on my 24th Buick and in the last 25 yrs have had not an oil related problem.of course I just use Quaker state 10W30. NB

[Guest]

Even our old car manuals say that you can change the filter every other oil change. Following that recommendation will save time, money and the enviroment.

[The Old Guy]

The straight 8 Buicks had a filter that only filtered oil to the overhead,and the best thing to do with them is chang oil often and filters seldom. I know many will say they don't want new oil going through an old filter ,but you can take the filter out and see that it isn't that dirty. I change oil depending on the usage of the vehicle. If it is run mostly on the highway ,I go as much as 7000. If it is short trips ,I will <BR>change at 3000. One thing I think is <BR>important is that when you put your car up<BR> for the winter ,it should have fresh oil so the bearings do not have any contaminants working on them over the winter

[JUSTIN]

I would think that I wouldn't have a failure due to oil being in there 5000 instead of 4000 miles. but I wonder about excessive wear on the engine due to the oil being older. any thoughts.<P>I drive my cars to the ground so they need to last a long time. I want 200,000 miles on the engine.

[Guest 70 Electra]

Boy, this one is almost as "near and dear" to my heart as the radial tire controversy! John Chapman is right on the mark, but I'd like to add a few comments......<P>1. Oil today is many magnitudes better than the oil that existed when our "old" cars were built. Engines are built better, too. That's a big part of the reason oil change intervals are as high as 10,000 miles on some new cars. It's NOT a conspiracy (as some people claim) to make cars 'wear out' faster and force you to repair or replace your car/engine!<P>2. Using "just" miles to determine when to change the oil is foolish. It is the type of operation the vehicle sees that depletes the oil. <P>My "day job" at a major auto company has allowed me to see engines that have run over 100,000 miles (under carefully controlled conditions) with NO oil change and still looked like new when disassembled. Conversely, I've seen 3000 mile oil that was totally trashed.<P>3. Many new cars use algorithms to look at trip length, oil and coolant temperature, RPM's and many other factors. HUGE amounts of research have gone into these programs to correlate oil depletion with predicted oil life. The results are excellent, and the systems work well.<P>My experiences with dozens of new cars with these systems is that they will tell you to change the oil any time between 3000 and 10,000 miles, depending on how you've driven. <P>4. By the way, one of the major reasons oil lasts so much longer nowadays (other than "better" oil) is the absence of lead in the fuels. Lead is both blamed and credited for many things, but lead from the fuel getting into the oil (blow-by) was a major contaminant of the oil. <P>(I remember in the mid-seventies, there was a SAE paper issued that discussed oil change intervals in a taxi cab fleet. They ran some on leaded fuel, and some on unleaded fuel. They used chemical analysis of the oil to tell them when the oil was depleted and needed to be changed. They found the unleaded fuel vehicles could run DOUBLE the miles before the oil required changing.)<P>5. It's ABSOLUTELY true that the "quickie" oil change places have a reason to encourage 90day/3000 miles changes. It's a revenue generator in and of itself, but also something that gets you into their shop. Once you're there, they will try to sell you other services. <P>(Note that the extended life (5 yr/150,000) of the coolant in many new cars has "robbed" the oil change places of another highly profitable operation. It's no surprise that many of them will try hard to convince you that you DO STILL need to change your coolant yearly, or bi-yearly!)<P>6. This one will raise a few eyebrows. We've done a lot of work on filters too. Other than the INITIAL filter change on a brand new engine, there is no reason to ever have to change the filter, other than to get the dirty oil out of it. Because this is not practical for most situations, the entire filter is usually changed for convenience.<P>Contrary to popular belief, on a new, modern, production line built engine, the initial filter change is not so much to get the "wear" (break-in) particles out, but to deal with the inevitable dirt and grit that is an unfortunate part of a production process. (These engine plants are not a sterile environment!) <P>After the initial filter change, the amount of wear and debris generated in a properly functioning modern engine is so little that the filter will last for almost indefinately.<P>However, as John Chapman pointed out, our old cars often have issues with blowby, and other contaminants. Regular filter changes make good sense.<P>7. I'd recommend using a quality, brand-name oil in all cars. Follow manufacturer's recommendations for viscosity in modern cars (usually 5W30 or 10W30) and use a 10W30 year-round in your "old" car. If you have a really "loose" and tired engine consider a higher viscosity multi-weight like a 20W-50.<P>Avoid the 10W40 oils (this will start some discussion, I'm sure!). It's a long story, but our testing shows these are not a good package. Notice that many automakers began advising specifically AGAINST 10W40 oils some time ago. GM even issued a service bulletin to dealers warning the use of 10W40 oil could void warranties. Why is the stuff even on the market? Because people will buy it. Not one manufacturer recommends 10W40.<P>8. Synthetic Oils. Surprised this one hasn't come up in discussion yet. These have two great advantages.<P>One, they do not thicken as much in extreme cold weather, and therefore make for easier starting. The other advantage is they hold up much better under extreme heat than conventional oils.<P>If you live in the tundra, tow trailers up Death Valley in July, or race your car, synthetic oils are great. If you drive in stop and go traffic, take short trips, and never see the temperature extremes, synthetics offer nothing. <P>The extended drain intervals for synthetics are for situations where the failure mode of the oil is thermal degradation (time at temperature). In short trip service, where contamination is the failure mode of the oil, the synthetics offer no advantage and do not have longer change intervals.<P>By the way, all the wives tales about synthetic oil are BULL. ("you can't break-in an engine with it", and "it makes the seals leak", "it increases oil consumption", you can't use it in old cars")<P>9. Having said all this, and with all due respect to the environmentalists amongst us, oil is CHEAP and it is EASY to change. There is no harm changing it early, so when in doubt, err on the conservative side (especially on your 'classic' ride!!).<P>10. Thanks for letting me "vent"!

[The Old Guy]

Greg, thank you for the very comprehensive report. You suggest that 10-40 is not as good as 10-30 or 20-50 and I would like to know why? I use 10-40 and it seems to work fine ,but if it is not good for my engines ,I can change easily.I could just as easily switch to 20-50 as the cars are notused in the winter

[Guest John Chapman]

Greg,<P>Well done. Thanks.<P>I spent many years flying/maintaining turbo prop powered aircraft. We used synthetic oil that was the lubricant in both the power section (turbine bearings) and the reduction gearing (fancy term for transmission). Oil was changed on the basis of results from an oil analysis program, with analysis conducted at every 100 hours of operation. Analysis was done more often for special cases (e.g. suspected running malfunction of a component, drive gears, etc.) We had some engines go thousands of hours without requiring an oil change.<P>Where all this is leading... For conservation of resources and more directly money, what would be the viability of a consumer-level oil anaylsis program based on the actual condition of the oil instead of a computer-run algorithm? I'd think the cost of analysis could be gotten to the point of $5 or so. With accurate information on oil condition, if you could routinely go 20-25K miles between changes, the potential savings are enormous. And this doesn't include the collateral savings of determining that there is a catastropic internal engine failure looming that could be caught during analysis and repaired before your very own Internal Combustion Armageddon.<P>Thoughts?<P>JMC

[Guest Roadmaster]

I have to disagree about using synthetic oils and getting oil leaks. This is only from a personal experience and not scientifically provable. I had a new 1982 Dodge van with a 225 6 cylinder. After about 6,000 miles and 2 oil changes with 10w30 I decided to put Mobil 1 oil in it. Very soon after I began using oil and also developed an oil leak. My mechanic asked what oil was in it and I told him. He suggested removing the Mobil 1 and putting in 30W. I did and in no time my leak went away, did not burn oil. I drove this van for 13 years and 120,000 without any other problems. Never used a drop of oil. Just my experience with synthetic oils.

[Guest 70 Electra]

Thanks for the kind words. Let me try to answer some of the comments/questions.<P>Joe:<BR>The short and untechnical explanation that I've been given by my company's oil engineers is basically what Gene Brink was alluding to. It's just plain tough to ask a non-synthetic oil to cover the wide viscosity range the 10-40 does. There are so many viscosity-modifying additives used to accomplish this, that it compromises some of the other characteristics of the oil. And, as others point out, a viscosity range this wide is NOT even needed in our typical products. <P>Bottom line: It may not make any difference in your car, in a hundred years. But then again, it might. So why mess with it???? <P>John Chapman:<BR>Conceptually, your idea is great. Logistically, there are some problems. Some truck fleets have used oil analysis for years. However, it's typically used on an audit basis, to establish service schedules--not to determine exactly when to change the oil in a specific vehicle. <P>If you think about it, getting a "good" sample can be just as expensive (labor) and awkward as actually draining the oil. You must have clean containers, access to the drain plug, remove the vehicle from service, etc. Then you need a good reliable lab, and timely results. A thorough analysis is neither cheap, nor readily available (at this time) in many areas. <P>Also, the constituents the analysis needs to look for and the level of concentration depends on the particular engine (what material in bearings), and brand of oil (and coolant,if there's any leaking into oil!).<P>My company can do this in a controlled dyno lab test, since the brand (chemical make-up) is known for the oil, fuel, coolant, etc. We KNOW how much lead or aluminum is a problem. We KNOW whether this brand of coolant uses potassium or sodium salts as corrosion inhibitors, so we can tell if there really is a coolant leak. (Did you know that small amount of glycol can actually disipate under elevated temperatures? Accurate coolant identification requires going beyond the simple glycol checks). <P>Anhow, my point is that it's hard to compete with a $20, 15-minute oil change. Perhaps when oil becomes over $2/quart, and disposal fees are twice this, there will be an economic incentive to do analysis on a large scale basis.<P>A much more likely (and user friendly!) solution is "in-car" oil CONDITION sensors. Sounds crazy, but the industry is working on them and they will be in new cars one day. Can't tell you any more about it than that, at this time.<P>Roadmaster:<BR>Don't know what to tell you. As you point out your experience is "non-scientific". It is stories like this that proliferate the urban legends and myths about synthetic oil. I can only say that the industry, and my company, have performed millions and millions of miles of testing on vehicles of all ages, types, and mileages and the synthetic has no drawbacks other than cost. Did I mention that it (Mobil 1, specifically) has been original equipment factory fill for the Corvette since 1992?<P>A comment on filters:<BR>I didn't mention before that filters have had major improvements over the years as well. Think that NOS PF24 from 1970 that's in your basement is just the thing for your freshly rebuilt GS455? Guess again. <P>Until the mid-to-late seventies, the AC spin-on oil filters had filtering media that would only capture particles down to about 60 microns in size. At this time, they switched to a medium that captured 40 micron particles. More recently (late eighties) they stepped up to a filter that goes down to 25 microns.<P>Keep that in mind when you find a "deal" on old filters (or off-brand, for that matter) at the swap meet!

[Guest John Chapman]

Greg,<P>So much for oil analysis... I'd not thought about the range of potential contaminates. With an aviation powerplant, you have pretty tight control on what goes into the works... and in modern engines, liquid cooling isn't one....<P>As a follow-on to your comments about oil filters, there was a web site at not long ago (link no longer works and search doesn't find it...) put together by a young MoPar fan. He'd undertaken a project of disecting all the current brands of filters and comparing the innards. The results were, to me, very enlightening.<P>For years, I'd thought of Fram as the premium filter maker... Not so anymore. Appaently they've fallen far in the past ten years. This would include Fram-made branded filters like Penzoil, Sears and several others. <P>The cream of the crop were AC-Delco and Wix (NAPA Silver/Gold). I can't remember all the details, but it was educational.<P>Cheers,<BR>JMC<p>[ 11-02-2001: Message edited by: John Chapman ]

[Guest Skyking]

Oldgsnut, I noticed you mentioned you use nothing but Quaker State oil. I had a problem some years back with Quaker State oil. It was leaving alot of condisation in the breather cap. It was always loaded with white form. I switched to Castrol GTX and never saw the problem again. I was wondering if any one else experienced this problem........Now I use nothing else but Castrol GTX in all my cars........

[Guest]

Some really great info here!<BR>I was scared at first that I was going to have to go hug a tree! (Just Kidding) I too have seen where some cars that leak oil at a multi-grade level will seal back up with a straight weight. I do think we change oil too soon here. In the trucking industry we have seen oil change intervals go from 10k a few years ago to some companies changing oil at 250-350k. Sure they use some snake oils (we have talked about that topic too) and change the filters but it's something to look at.<P>Some of these companies are using a centrafuse system which spins particals through a system of screens, which can be taken off, cleaned, then re-installed. Your talking serious savings in the long run.<P>Back to the subject of oil. Here is my opinion, the oil shortage (story) is just the BEST way for the oil companies to keep robbing all of us blind for this so-called RARE product. We will never run out of oil, but before we would even get close to running out we will have a better product to replace it. We have already seen those trends, I wonder if back in the days when things were powered by steam people were crying about a steam shortage? A REALLY long time ago I bet the cavemen had a lobby out trying to save the stone! Better slow down making those wheels.<P>I say NORTH TO ALASKA! The new gold rush.<P>Just my opinion.<BR>Duane

[Gene Brink]

Interesting thread here and I'm just going to add a couple of things I've run across over the years.<P>1. The ability for the oil to mimic different weights is due to additives that chemically permit the oil to have flow characteristics matching that of different single weight oils across a temperature range. This ability for oil seems to be effectively limited to an range of approximately three grades (i.e. 10-30, 20-50). While 10-40 isn't necessarily bad (remember, it does have to pass the same SAE tests to get its rating) it is not as effective at either end of it's range as oils with a lesser range (which is also true with 10-30 & 20-50 but the difference is not as great). I think this oil is around because some people think they are getting more somehow but I can't think of anyplace where the temperature extremes would make having such an oil necessary.<P><BR>2. Check out your local library for a back issue of Consumer Reports (a few years ago) where they tested a number of motor oils. They too found that 10-40 does not cover all ranges as good as a straight weight oil within the range would at a given point. They did a pretty good job of explaining in terms one can understand (however I have forgotten most of what I read). They also had some interesting things to point out about the minor differences between oil brands (which may not still be true).<P>My personal experience has been that I have never had an oil related failure of any type in any car I have owned and the same is true with my parents' cars over the years. The common denominator is regular oil changes. In fact the '52 Super we had growing up had a bit over 160,000 miles and was driven to the junk yard (we got $15) when it was replaced by an '66 LeSabre. The only oil used was Mobil straight weight 10 (my dad's reasoning was it would get places heavier oil would not) after the initial oil change. The car was not babied and made multiple trips from California to Ohio to visit grandparents.<P>Gene

[Guest]

my few cents worth here<P>John: I don't know if the site you're talking about is the same one I've seen before, but it does indeed suggest ACDelco, Wix and Mobil are the best filters. That site it still out there, but I can't find the url either, go figure.<P>Skyking: Ya have another vote for Castrol GTX here. Other cheaper oils just aren't (imho) as good, nor last as long.<P>Nailed: North to Alaska eh? Sure, why not, we're tearing down the rain forest, why not take the rest of what's left to the crapper for greed.<P>On the topic of oil changes, I also think that if your engine leaks it, and your adding oil every week then the change interval should be extended proportionally.<P>my opinions are mine, not forced upon anyone and open for critizism (which i'm sure i'll get)<P>-Scott

[Guest 70 Electra]

"Nailed 1", I liked that comment about the cavemen having a lobby effort to save rocks! (LOL) <P>An insightful observation was made about "leakers" extending the oil change interval. That's actually quite true. Any vehicle that has new oil added (either due to consumption, or leakage) can effectively have its oil change interval extended. <P>Each fresh quart represents "renewal" of approximately 20% of the engines capacity (assuming the typical 5qt system). Arguably, if you consumed enough oil, you would never have to change it! Most of us, I'm sure, will repair our engines before things ever get that bad!!

[Guest]

Scott,<BR>Did you get to enjoy some power outages this year? Your leaders think the same way, which is exactly why you had people dieing from heat. Which is more important? I don't have a problem with conservation, but when it involves the Government dictating who gets what when, I see how far we have fallen and it bothers me.<P>The rain forest and Alaska oil share a often forgotten key point. The people who live around and in the rain forest are the main ones cutting down the trees for the development of their people. The same holds true in Alaska, the people who live there want it most. Who am I to tell those people that no you can't build an industry to better your state and you well being?<P>Its kinda like telling the indians they can't have the gold they live over!<P>Sorry so long and far off the topic.<BR>Just voicing my opinion while I still can, let the feds take a little more of our freedoms and we may not have that right much longer!<P>Duane

[Guest]

Great topic as I am in the process of rebuilding a motor. I was talking over this very same issue about what oil to use. Now the engine has been slightly "improved" with 10:1 compression forged pistons, .500 lift 232 dur cam, (and other goodies) we estimate close to 350hp. That said, would running 10w-30 be better for the engine than 10w-40 - even in a "performance" street engine?<P>Whatalark

[Guest 70 Electra]

As earlier postings from me (and others) have indicated, 10W40 should be avoided. See previous topics for the reasons.<P>My advice? If the bearing clearances on your rebuilt motor are "stock" (relatively tight), stick with 10W30. If you've opened the clearances WAY up, like for racing ("loose to go fast!") then go with a 20W50.<P>Either way, change the oil and filter promptly, after only a few miles/hours after initial start-up. Also, when firing it up for the FIRST time, don't let it fall below about 2500-3000 rpm for the first 10 minutes. This is critical to new camshaft life (I'm assuming a NEW camshaft and lifters). Lastly, if you haven't fired it up yet, consider "pre-oiling" it by using a dummy distributor shaft and electric drill to prime the oil pump and get oil to the top end.

[Guest]

[last post to avoid possible argument]<P>If you want to read my reply, click <A HREF="http://cyberbuick.servebeer.com/bca/~public/reply.html" TARGET=_blank>here</A>.<BR>I'm not posting it here so that it's optional viewing.<P>Whatalark: The general consensus from what I gather is 10w-30 on new/rebuilt and 20w-50 on a higher milage/loose engine. Personally, my drivetrain noise subsided somewhat when I switched from 20w-50 to 10w-30. Tack själv Anders!<P>my views and opinions only,<P>-Scott<BR>(lame server coding! argh!)<p>[ 11-04-2001: Message edited by: CyberBuick ]

[The Old Guy]

Valvoline just came out with a new oil for higher mileage engines.Any comment on this product??

[Guest]

The Old Guy,<BR>Is this new oil Synthetic or mineral? I have not seen it yet.<P>Duane

[The Old Guy]

The new Valvoline is called Max-Life and it supposedly has additives that will help higher mileage engines. They say it will help older seals and I just wondered if this was all hype or if it had some basis in fact.

[Guest 70 Electra]

Old Guy,<BR>You hit the nail on the head (nailhead?).<P>This "new" oil is a marketing gimmick only. Competition keeps the prices of "normal" oil incredibly LOW. At these cut-throat prices, the companies make little or NO money on the product (they rely on gasoline profits and sale of oil to auto manufacturers like GM).<P>As a result, there is a profit-driven marketing incentive to develop "upscale" and niche market oils. (Remember the "special" Turbo oil? the "special" Truck/SUV oil?) The idea is that people will pay extra for the status and perceived features of the "upscale" oil.<P>This new "high mileage" oil is just such a special "upscale" profit-making product. Note that the ONLY claim they make with this oil is that is MAY help sealing. Specifically, it has an additive that swells seals. Nothing more, nothing less. <P>So, IF you have leaks at seals that are due to wear of the seal, or oil consumption due to valve stem seals that are worn, this swelling agent MAY help you.<P>Normally, it is desireable for engine oils to have properties that DO NOT swell seals. As you can imagine, "swelling" or enlarging seals that do not need it, will simply result in premature wear and other problems.<P>If your experiences are anything like mine, the problems you've seen relative to seals are not necessarily things that will be solved by swelling..... If the valve stem oil seals are hardened (or so brittle, they've fallen off!) "swelling" them won't help. If a crank seal is leaking because it is cut, or because of the groove worn in the crank nose, "swelling" won't help. If your oil "consumption" is due to hard cracked leaky cork valve cover gaskets, a seal swelling additive won't help!<P>Personally, I'm disappointed with Valvoline for offering a product of such a questionable nature. They are a quality refiner and their "normal" oils are among the best available.<P>I suppose this could be a "good" oil for a used car you're going to sell.

[The Old Guy]

Thank you for the prompt reply. After reading this post, I will go to 10-30 regular Valvoline and try to stop believing all the propagnda put out by the oil companies. I have run valvoline for years ,but I got snookered by the Max-Life BS