Slick 50 and Synthetics

z71bill

But in 50 years I would not be surprised if electric engines that produce 500 HP, run for 2 years or 50K miles between charges and weigh 50 pounds are the norm. Of course they would have optional V8 engine noise piped in through the speakers just to make it feel like you had a gas burning V8.

mgdvhman

car owners do for gas??

Gas is here for a long time.....a very long time..

We have billions of tons of it!

- Tim

z71bill

You will still be able to buy it but because 99% of the new vehicles will run on something else the number of gas stations will shrink and the price will go up to $50 per gallon. But people will still say "give it some gas" when they want you to speed up just like many people still say "dial the phone" Are we getting too far off topic or have others not gone far enough?

mgdvhman

Not farr enough!!!

y2kgmc

I switched to mobil 1 0w-30w @ 835 miles in y2k GMC Sierra ,will it still break in properly .I think so ZR1 vettes come from the factory with it

tech

i would like to add my .02 to this discussion.
i work for a major high tech manufacturer of semiconductors hopefully this will establish some credibility with the following comments on this issue. i have been interested in the debate over
synthetic vs hydrocarbon oils and the benefits or lack there of for quite some time. i am not chemical engineer but i do work with several men and women who are and have held several conversations with them on this very topic. they all have said there are distinct advantages to synthetics over the hydrocarbon based oils. the difference is whether it matters to the individual. i know that i am tired of people speaking witout bothering to research the issue and giving accurate information to others. just because they drive cars and change oil doesn't make them experts on cars and oil.what follows is the results of my research and the facts as far as i can determine from the resources available to me.
the facts are as i have determined,
1. what makes oil good or bad is the base stock of the oil.
it is either based on hydro. or synthetic stock.
2. the best base stock known commercially is polyol esters oils based on this stock are
1. red line
2. neo
3. amsoil ? i'm not sure of this one
the polyol esters are the oils used in commercial jet aircraft turbines because they are the only stock that can withstand that kind of stress and heat. they also are more expensive this is where you decise if it is worth the expense but they do out perform all other oils by far.
these are known as premium synthetics
the next level are based on polyalolefins agoood base but don't perform as well but definetly better than hydro based oils.
these are mobil1 valvo. etc. these are about half the price of premium but still more than hydro oil.

i use the premium because cars today are to expensive to replace if you don't have to. i also have found that with wxtended drain intervals and better filters the cost is not that much more. only you determine if it matters to you. i hope this helps someone.

bud_light_dude

Thanks for the info, but just because you converse with an Engineer doesn't make your information any more factual or any less opinionated of what is better than another. You just said the same thing that, in your words, "the common oil changers have said".....something that irritates you so.

Hi tech semiconductor field of expertise gives no credit to chemical engineering researched data.

I am a Computer LAN Systems Architect. Doesn't make me any more creditable about oil refining or an oil's chemical composition.

Not attacking, just pointing out that you have essentially done the same thing you said irritates you and what you have discredited others here for doing. Practice what you preach.

tech

allow me to point out to you that semiconductor engineering is all about chemical engineering. the processes are all designed and qualified by chemical engineers. i certainly think and i believe that you would agree their education in the chemical field most of which is geared to the petro chemical field (their words not mine))and experience gives them a little more credibility than the average joe. i'm sure when it comes to computer architecture you would like to think that your education and experience would carry more credibility than someone who just bought a computer and plugged it in all by himself . my intention was to bring out the facts concerning the issue from people who have studied and researched scientifically at the molecular level and not have misinformation spread like wives tales.
in no way was i trying to insult or put anyone down but on technical matters such as these(scientific properties of petro chemicals) it is not a matter of opinion. certainly we are all free to use this information or not.

rrichf

A-Men!
Synthetic base oils may have longer intervals between drain and refill. Synthetic may protect the engine from wear better.

The only problem is that we'll have to tear the engine down at the million mile mark to see the difference. Would any of us "common oil changers" notice any difference at 250,000 miles? Would the added cost be worth it?

Who knows! Who cares? My truck will be gone by 300,000 miles and I sure as heck won't care one way or the other. Will an oil related failure prevent me from reaching the 300,000 mile mark? I doubt it.

On a diesel engine, cleanliness is next to Godliness and you have to remove the soot from the oil. Change at 5,000 and don't worry if the synthetic chemical base is removing the soot.

I guess that's a whole bucks worth.
Rich

bud_light_dude

Lets just say that I have a very extensive backround in electronics, both from a design and from an application perspective. I have never been involved or had a need to know about chemical compositions with the exception of doping of certain semi-conductors, i.e. op-amps, transisors, rectifiers, etc. There are tons of books already published that eliminate the need for my having to know chemistry and properties of related materials.

How does your involvement with semiconductors give you expertise or any more credit about chemical engineering? That was my point.
Your backround doesn't sound any more credible than mine in electronics and engineering(by education) and my work experience in networks (by work experience) and I don't claim any more credibility on this subject than someone who just owns a truck or car and changes their own oil.

Enough said. It just sounded like you were calling the kettle black. Manufacturing semi-conductors is a lot different than manufacturing oil. If you have a degree in chemical engineering, which would give you education on all chemical engineering, I will retract the intent on my last post. It sounded to me like you were not a chemical engineer by education and only make semi-conductors by work experience, which would not give you credibility in chemical engineering, just making semi-conductors.
I know this because I worked in a clean room making semi-conductors while I was going to school. I didn't need any special education or backround, just on the job training.

mgdvhman

sensing when a topic has become too anal!!

Come on guys...share info...not doubt the knowledge of each other!

- Tim

adolart

25 years with many diesel engines, the synthetic kept the engines clean, running and in good shape, started in very cold weather, never had one use oil, the most important item is buy the best filters you can find.
Synthetic oil (Amsoil) boils around 450 deg and will poor down to -50 deg. Regular oil boils at a much lower temp and we all know how bad it poors when it gets around 0.
At 300K in a Cat engine, I had to change the clutch, at that time I removed the oil pan and checked the bearings with electronic gauges, all were like new readings.

tech

last time i address this bud dude, i never said i had the experience in chemical engineering. maybe you need to lay off the bud and drink milk or something and you won't have so much trouble comprehending. thanks to mdgvhman my intent was simply to share info. whether anyone accepts or believes doesn't matter to me. if i don't know something i go to those who do know and then i can speak with a fair amount of intelligence.
200k miles may seem like a lot to some but from what i read and researched 500k is very realistic. i for one want to hold on to my vehicles as long as possible spending hard earned 20k+ dollars on more enjoyable things.

bud_light_dude

Sorry. Didn't mean to ruffle your feathers in the hen coupe.

I drink Bud "as" my milk. Never will I stop.

vince4

One thing no one has pointed out is the saved time and effort with extended change intervals when using syn. If you change regular oil at 3k miles you can easily double that and still be less than the 7500 recommended by the manufacturer. Amsoil recommends 25k miles or 1 year with regular filter changes. That is more than I could handle but it points out how durable this oil is.

You can go a lot longer on syn oil and still provide better protection because it doesn't degrade like regular oil. So you get better protection and less work at the same time. Plus the longer interval helps offset the cost. Sounds like a good combination to me.

wburbank

No one has mentioned anything about Red Line syntheic oil. They have a web page www.redline.com I would like to hear some feed back on this product from some users. According to them, they are the PRIMO brand. Any comments.

I have ordered a 00 Ford F250 Lariat PSD CC SB. By the way I got it at dealer cost. Figures matched with carsatcost.com Hope to have it by March 1-15, 00. So I'm checking out all sorts of stuff to make this puppie purr for a long a time.

Have a good one.

bud_light_dude

Redline is a good oil, but their technology is still far behind Amsoil. I compare Redline oil to Mobil1 oil. Very good, but no comparison to Amsoil. Mobil1 is much cheaper for basically the same level of protection. If you want a good oil, but not the best in the business, Mobil1 would be preferred to me over Redline oil because it is much cheaper.

Amsoil was first in the consumer synthetic business with an API rated oil. It was based on the high temp and stringent API ratings of the lubricants used in Jet Fighter Aircraft.

Amsoil has a complete line of products for every application imaginable. The base stock of Amsoil is still far better than any other in the business. It is costly, but you get what you pay for. Redline isn't making "SUPPORTED" claims of 25,000 mile or 1 year change intervals on their oil, thats for sure!

Go Amsoil if you want the very best for your vehicle. Oil tests have proven it to be the superior choice in synthetic lubrication.

tech

red line oil is nothing like mobil 1 . red line oil uses the same base stock as amsoil (polyol ester)mobil 1 uses a cheaper base stock. don't recall the chemical name right now. i don,t know what tests are referred to but dynometer testing has shown that nothing was superior to red line . it wouldn,t surprise me to find that amsoil results would be similar to red line since they are chemically similar. this is not to say that amsoil isn,t a good product. wonder why it's not sold retail?

bud_light_dude

Amsoil IS sold retail the same way Redline oil is. Same as Reline, you just can't buy it at Walmart and KMart. You have to be screened and get approved to sell at your commercial establishments. They won't just sell it to any company wanting to make a buck. You have to be knowledgeable about the product.

Redline's vescosity, temp, breakdown, etc is not as good as Amsoil. Even just comparing each companies publicly posted specs on their websites will prove Amsoil has been and still is the industry leader in synthetic products. Redlines oil does not maintain it's vescosity at 45 degrees below zero like Amsoil for instance.

If you like Redline oil, thats fine. I never intended to imply that Relines "composition" was similar to Mobil1's. What I said was that it's protection qualities are comparible and Mobil1 is still cheaper. Redline does not have near the protection quality as Amsoil. Redline is comparible to on the shelf products at Walmart or Kmart in this respect, but not a bad oil by any means if you don't mind paying too much for it. Again, the specs are highly regulated and they can not be incorrect. Compare the two companies. If you know what you are looking at and understand what each spec means, it is a landslide difference to Amsoil's favor.

Also, Redline oil does not make a "full line" of products. Amsoil has a complete line of products for the car and truck.

Another note. I used Relines Sl1 fuel treatment for a short time. I noticed that when the Sl1 was placed in temps below 30 degrees F, it quickly gelled up. I wonder what that does in a gas tank in the Winter time. That proved that particular product to be crapola. Amsoils fuel treatment did not gel up at all, even when placed in a freezer. I called Redline's support number. They denied that their Sl1 product would gel up at any temp. That in itself is reason enough not to trust anything they make.

tech

i'm always willing to learn new things. i've been searching for the best product available and went to the websites of both and found you are correct the numbers show that the amsoil seems superior even though they have similar chemistries.
what do you or anyone else know about royal purple synthetic oil out of texas? is it comparable to amsoil?

mgdvhman

may not be the absolute best....

but for the money...nothing compares to it.

It protects much better than conventional oil for the average everyday Joe.

If you are running a jet engine Powered Chevelle....then I guess Amsoil or Red Line would be the choice.

every other application....Mobil 1

- Tim

tech

for virtually the same money why not run the best? amsoil is 5.25/qt mobil 1 4.00/qt

bud_light_dude

I won't argue that Mobil1 would be my first choice for a synthetic that can be found readily, but if you really research the benefits of Amsoil, it makes sense to use it over Mobil1 even for applications other than race cars or jet aircraft. Yeah, its more expensive intially, but not by much and you don't have to change it at 7,500 max change intervals like Mobil1. Oil tests on 25,000 mile Amsoil with regular 5,000 mile oil filter changes has proven to have less breakdown and more stable vescosities than Mobil1 at 7,500 miles. That is a very important note about Amsoil. They are the only synthetic oil company that you can utilize the 25,000 mile oil change intervals and not void your oem warranty.

Tech: I do not personally know of Royal Purple's specs. I have heard of it, but only have researched the oil that has any competition with Amsoil and Royal Purple is not a strong competitor to Amsoil OR Redline oil. To me it is not even an option.

I am sold on Amsoil, even for my daily driving and light duty work use, it is the best for my money. Redline would be my second choice if money were not a concern. I just think that the protective qualities of Redline are pretty close to Mobil1's and Mobil1 is less expensive so if I had to buy my oil retail, Mobil1 would be my choice over Redline.

tech

dude,

are you using amsoil filter or standard commercial brand? it seems that with amsoil it doen't breakdown under normal driving conditions that the determining factor as far as longevity is concerned is the filtration (particle size, efficiency, longevity of the filter) do you agree?

mgdvhman

what oil you choose.

No oil is staying in my crankcase for 25,000 miles.

5000 Intervals is just fine.

- Tim

bud_light_dude

No. The breakdown has nothing to do with the filter used or how frequently it is changed. The filter changes only filter out dirt and blow by gases that enter the oil from driving conditions.
The breakdown is caused by heat, friction, and other variables.

Tim:
Your preference is fine. However, the Amsoil still provides better protection at 25,000 miles than the Mobil1 oil does at 5,000. The facts are in the research and study since 1972. Mobil1 has only been the last few years.

Mobil1 one is not a bad choice, but it is a fact that Amsoil is better, even at 25,000 miles of use.

mgdvhman

Yikes!

Good Luck

- Tim

markcord

It's going to be hard enough to get used to leaving oil in for 5000 miles (just switched to Mobil 1 also). 25,000 for me is just unthinkable.

bud_light_dude

People overspend for more "security" in their maintenance to increase longevity everyday. I understand your reluctance. Truth be known, you could go 5,000 or even 7,500 miles on conventional petroleum based oil and still have plenty of protection. The premise you speak of about so frequent of oil changes is the same reason people want to use high octane fuels and slick 50 (junk), mystery potions, fuel additives, etc.

It's your money. No body should tell you how to save it or spend it more wisely.

Amsoil will still provide better protection at 25,000 miles than Mobil1 at 5,000 miles and your oil change maintenance costs would be reduced greatly. The oil sample analysis by Amsoil or even other testing facilities will prove this beyond the shadow of doubt 100% of the time.
This is where the initial cost of Amsoil pay's off. People are just reluctant to change their paradigms and stick to the things that keep making oil companies rich.

Again, it's your money. Save it or waste it, makes no diff to me.

bud_light_dude

Why would Amsoil claim the 25,000 mile oil change intervals if it were not true. If their intention was to just make money, wouldn't you think they would claim the same change intervals as other oil manufacturers? Increased change intervals would make Amsoil more money. The cost of their oil is not that much more money than Mobil1 so with less frequent oil changes, you definitely are saving money. Why would Amsoil do that if their only concern was to make more money?

Change your oil every 3k like oil companies have claimed was necessary for years. 3-5k intervals is only to make the oil companies more money.

arkie6

To bud light dude: The reason Amsoil claims a 25,000 allowable oil change interval is for marketing purposes, whether fact or fiction. If they can get you to justify the higher cost of Amsoil with a longer change interval, then they make money. If they cannot get you to justify the higher cost, then they make no money. You have obviously bought into this and that's fine; however, I am more comfortable using Mobil 1 and changing every 6000 miles.

mgdvhman

7500 miles is OK for conventional oil....hell..GM says to do so in the manual!

3000 is overkill.

When you get a rocket scientist to analize Amsoil at 25,000 and Mobil 1 at 5000...perhaps amsoil may be the slightest tiny teeeny bit better in some kind of aspect that we will never even need or notice.
Bottom line - No person driving any car/truck needs anything more than Mobil 1....period.
You can sling all kinds of "amsoil say so" stuff in my face....but bottom line...I ain't keeping the oil for 25,000 miles....period.
Yeah you may have used 5 filters by then...but no filter can take out all the crap that has accumulated in 5000 miles...much less 25,000.

We were once told that "everybody needs a Yugo"..does everybody need Amsoil?....No....Does anybody really need amsoil that drives a car or truck?....probably not.

I drive 80 most of the time for long highway stretches and want an oil that is better than conventional when at those higher speeds....so it does not break down. Also wanted an oil that would flow faster at cold temp.....Mobil 1 provides both.
While Amsoil/Red Line may claim better....it's overkill.
I totally understand some people wanting to go for overkill. We all probably have some options on our vehicles that are really not needed...AKA overkill.
If you want to use way more than you need...go for it...I decide to use something more practical.
If you want dirt flowing through the engine for 25,000 miles.....go for it.

I'm sure the product is better than Mobil 1....but not enough to get excited about..

Good Luck

- Tim

rs_petty

One reason I went with M1 is because it was available at most any Walmart/Kmart/gas station in the country. Hopefully, I'll never need a repair on vacation trips that will cause a oil/filter change, but if I do then I know I can get the same oil to replace it. I'd either have to tote it or wait several days mail order for Amsoil/Redline.

markcord

#155 and #156 are right on the money as far as I'm concerned. I'd never even heard of Amsoil, let alone seen it, until I happened upon this topic. Sounds like great stuff, but M1 will do just fine for me. As far as "frequent" change intervals (3000-5000) it's just that much more insurance against not necessarily worn oil but probably dirty oil.

tech

dude,

i agree with what you are saying, i am employed as a tech in the semiconductor industry and the fact is 10 micron filtration is more than adequate for automotive purposes or for that matter most applications.

a few posts back i referenced an article in one of the popular mags(science i believe) to recap they took 10 nyc cabs and ran 5 with amsoil for 70 k miles and 5 (the control group) with dino oil changed every 3k miles. when the oil was analyzed they found 6x more bearing material in the control group oil. that is a striking statistic. it is enough to make me at least investigate amsoil.

i also understand mobil has changed (downgraded their base stock) at one time they advertised 25k change interval. but they switched to the less expensive polyalphaolefin base which does not have anywhere near the characteristics of the amsoil base stock. i also heard that red line has reduced the quantity of polyester in their formula making it inferior to the amsoil formula.

tech

the oil was analyzed at 70,000 miles. this alone would speak volumes

arkie6

bud light dude, are you a distributor for Amsoil products?

mgdvhman

BLD,
I know that Mobil 1 is over kill....I just choose not to go one further step of overkill as you do.
I have heard of Amsoil and know where to buy it. Red Line I have not heard of.

I use filters in my kine of work that filter water down to 1/2 micron..so 10 seems pretty huge..(just kidding..have a beer)

Chew on this....say you had a slight crack in block or wherever and coolant was leaking into the oil...I'd rather find it at 5000...then 25,000....wouldn't you?
What about just good old condensation which can happen?....you want that in there for 25,000 miles too?

Another thought is...when i sell it...I doubt very few people have heard of Amsoil....everyone knows Mobil 1. I'll have about 45,000 miles when I sell....and I don't think the buyer will be too happy when I tell him I changed it once in 45,000 miles....."But I used amsoil!!"

As for -45 degrees flow rating....I have nothing what so ever to worry about ever getting anywhere near that temperature....as I'm sure no one on this entire board does as well.

The flow difference between Mobil 1 and Amsoil does not apply to any of us....the flow difference between Conventional and Mobil 1 IS something we can take advantage of.

I don't doubt it's a better product...but it has no logical use for any of us in passenger cars and trucks....end of case.

- Tim

z71bill

February 2000 issue page 30 has a good article about synthetic oil. It is all positive about Mobile 1 claiming reduced friction, more HP, 5% improvement in gas mileage. Then at the end of the article John Tichy Ph.D. of Rensselaer Polytechnic Institute sums it up by saying "unless one drives extensively, or under extreme conditions, they (synthetics) offer no clear benefit" If synthetics reduce friction, increase HP & improve MPG how can this be no benefit?

Other points:
Silverado maintenance schedule does not recommend 7,500 miles between oil changes - It says NEVER GO LONGER THAN 1 YEAR OR 7,500 MILES BETWEEN OIL CHANGES. My oil change light came on today after only 3,337 miles. I drive in town short trips.

Oil filter - 100% of the oil does not go through the filter, they have a by pass for the excess flow. If your filter was plugged would your engine stop pumping oil..

Changing your filter and not changing the oil- If I go to the trouble of changing the filter I may as well take the extra 3 minutes to change the oil.

mgdvhman

well wouldn't never go longer than 7500 mean every 7500?

I'm going approx. 5000 or so with M1

- Tim

z71bill

Not in my opinion. It would depend on how you drive. If you have 90% highway miles then yes 7,500 would be ok. If you drive stop & go city then no way would I wait that long. Like I said my change oil light came on after 3,337. It matches what I expect because I have many short trips, most are less than 15 miles. I may give Mobile 1 a try, but would still change the oil when the light comes on. Oil and filters are cheap - even with Synthetic total cost is only $30. It is worth that much to me to keep clean oil in my truck.

bud_light_dude

1/2 micron would not even let oil pass. .5 micron takes an extremely long time to filter water, let alone oil.

I just used the -45 degrees vescosity as one benefit and point. I know nobody will actually be at that temperature with their vehicles. But that just shows how much benefit Amsoil provides as one point.

As far as the 25k mile hang up. There is a 7,500 mile oil made by Amsoil that is still better in all the qualities than Mobil1. If the 25k mile hangup is a problem, use the 7,500 mile oil AND filter change interval.

As far as moisture or coolant being in the oil, do you not check your oil at least once a week. I do. If you are particular enough to use a synthetic, I would guess you are particular enough to check your oil frequently also.

As far as selling your vehicle after using the higher oil change intervals, all you have to do is show the buyer Amsoils guarantee and GM's signed document that they support the oem warranty while using the Amsoil 25k mile change interval. That is correct. GM fully supports Amsoil's 25k mile oil change interval as long as the oil filters are changed as specified 5k intervals. That is in writing. The oil sample analysis tests prove that Amsoil protection at 25k miles with 5k filter changes still provides better protection than any synthetic oil at 5k oil AND filter change. It is no different than keeping oil and filter purchase receipts to show when oil was changed if you change your own oil.

Little does anyone know, but very soon Amsoil will be the bulk oils used in most all your lube service shops. It is very quickly taking over the valvoline and pennzoil shops as well as being used more and more in the mom and pop shops. It plain saves the shop and the customer money.

I respect your desire not to use it. I don't even claim it is the best choice for everyone. However if you are going to use a synthetic, Amsoil pays for itself very quickly if you just research it out.

As far as the guy who stated he might as well change his oil too if changing the filter. I don't get that. You only lose less than a quart of oil by changing the filter and it takes longer than 3 minutes to fully drain and replace the oil, not to mention you are throwing away perfectly good oil. Why? That is such a waste.

To the person who asked if I am an Amsoil dealer.
No. I am not. I just researched it out and found the best for the money. I just started using it after about 3 months of proving their claims were correct. I am 150% sold on Amsoil, even if the slightest bit inconvenient. It is worth the savings and the quality of protection. I am seriously considering becoming a dealer though. Around here, the stuff sells itself. My GM dealership stocks it for it's elite customers who want it over Mobil1. Mainly corvette and caddy owners. I could probably get contracts with most of the local shops around here too.

I don't mean to push Amsoil on you. I respect and fully understand the reasons you all prefer not to use it. I said and felt the same things. That is, until I did the research myself and proved it to save me money and provide better protection too. I won't make Bubba Walton any more money on oil from now on, that is for certain.

mgdvhman

the 1/2 micron was a joke.

I see neither one of us is going to budge.

Good luck

- Tim

rs_petty

Why is there a distinction between in town driving and highway driving in terms of engine oil performance? How long does an engine need to be at operating temperature before the so called "condensation" burns off? (Which is the only possible downside to short trips.) I challenge that an engine driven within design parameters doesn't care whether it is highway or city and neither does the oil. The computer monitors only measure cold starts so I don't think they are necessarily a yardstick for oil changes.

rrichf

rs_petty,
Doesn't "In Town" imply more idling and more frequent starts? Is it possible that an engine is running richer at idle and therefore more fuel contaminants reach the oil? With more frequent starts is there the possibility that there is more raw fuel contamination of the oil as well as metal grindings?
Rich

arkie6

In town driving is harder on an engine and oil due to more frequent starts and opertion when the engine is cold. A cold engine will have more combustion gas blow-by due to looser tolerances on parts to allow for thermal expansion when the engine is hot. For instance, the piston rings have an end gap that can be measured (say approximately .010") when cold but I bet there is less than .002" gap when hot (kinda hard to actually measure). Anyway, combustion gas blow-by will contaminate the oil and also, the previously mentioned issue of condensation is a concern on frequent short trips.

rs_petty

Those could be "in town" scenarios, but it could also include a 10 mile trip at 40-45 to the commuter lot versus "highway" where you live 1/4 mile from the on-ramp and you jump right from a cold engine to 70+ mph for 5 miles. Which is harder on your engine? I'd say the highway miles. My point is that stereotyping city driving as harder than highway miles may not always be true, therefore the argument that says you can go further between oil changes if you do highway driving is not always true. Also, for the engine, that city driving is not necessarily any harder on your engine than highway miles. Other components (brakes/transmissions) may get more abuse, but I don't think the argument is relative to the engine and engine oil unless you give it a specific scenario that includes a certain number of cold starts and not getting the engine to operating temperature. Fuel injected/computer controlled engines are going to maintain the fuel mixture to a certain parameter not necessarily rich at idle. My dad would put 50-60k miles a year on a car in his business with about 90% highway. Changed oil at 6k intervals and always would have valves clicking and blue smoke at about 60k. But, then this was in the 70's when maybe oil and engine technology were not up to snuff.

andy_jordan

the real hard work happens when the engine is cold - so highway / city can be misleading if all cold driving is done in the same type - my typical daily commute is 95% highway, but when cold the balance is 50 / 50. I would also argue that my brakes / clutch get a hard work out on the highway because of variable traffic volume.

Like evrything in life it is never that simple. I think that the typical difference in maintenance schedules that is indicated by manufacturers really gets to the point. They suggest maintenance more regularly in various scenarios - dusty air for example, but also if there are a high number of short trips - essentially where the engine never really heats up and the oil is therefore working harder - and becoming more contaminated, as previously discussed.

z71bill

Use some common sense - Highway miles implies longer trips - like driving 50 or more miles per trip (at 60 MPH) ,not driving 1 mile on a highway at 75 mph.

Also do the math. If you drive 7,500 miles at an average speed of 60 MPH your engine has ran for 125 hours. If you drive the same 7,500 miles at 20 MPH it would be 375 hours.

rrichf

Andy J,
You bring up an interesting point, the dusty environment. In a dusty environment I understand the logic for the need to change an air filter more frequently. Why the need to change the oil and filter more frequently? Never thought of it until you mentioned it. In the modern engine, the crankcase is sealed to dust and dirt. What is the logic behind the manufacturer's recommendation?
Rich