I've seen that site before, as well as others, and nothing in it seems surprising. In fact it supports my earlier comments. I don't waste time talking about dino oils because for normal use they are practically interchangable. However, one statement on that web page need to be taken to heart by 4x4 drivers...

"The extended oil drain intervals given by the vehicle manufacturers(typically 7500 miles) and synthetic oil companies(up to 25,000 miles) are for what is called normal service. Normal service is defined as the engine at normal operating temperature, at highway speeds, and in a dust free environment. Stop and go, city driving, trips of less than 10 miles, or exterme heat or cold puts the oil change interval into the severe service category, which is 3000 miles for most vehicles. "

Hey, its your engine. You do what you want to. But I am perfectly happy running synthetics in my vehicles and will continue to do so until something makes me change my ways. By and large, so many people disregard basic upkeep, I'm even amazed that we have these discussions about oil.

Here's a question... how many of you actually flush your cooling system at the specified intervals? Or how many of you flush your brakes fluid every 1-2 years? Think your dealer is doing it? Ask them.

-P

There's absolutely nothing wrong with using a synthetic oil. I just can't justify the price difference when dino will run for 5,000 - 7,500 miles. I took my Tacoma off road, and drove in dusty conditions, and had a K&N filter in it which supposedly lets more dirt in blah blah blah. My oil analysis came back with great results after 5K miles.

Synthetic oils may not break down as fast, but they still absorb dirt at the same rate as fossils. That's the issue I have. Using a top of the line oil filter is also a key factor to oil longevity. I've been using Mobil 1 oil filters for some time and am quite happy with them. Too bad they're so expensive.

I actually did a lot of research on oil filters as well, Look at this , and found a Purolator PureOne oil filter is just as good as a Mobil 1, and costs 50% LESS. Too bad it's not available for the Xterra 3.3L V6. I've e-mailed Purolator and they have no time frame for this either.

As far as radiator and brakes go, I use the "Multi-Meter" test on my antifreeze. You can put a Multi-Meter into the fluid, if it registers a certain amount on the meter, the liquid is still good. If it's over a certain number then it's becoming acidic and needs to be changed. I'll have to find my book on the actual number, but I believe it's up to .10V or something like that.

Brakes, I bleed and flush the system when the fluid becomes dark. That is usually not in a single year but more like 3-4 years.

Toy4x4Guy-
Yes, having my 25,000 mile oil change intervals do justify higher oil costs per quart. It is much much cheaper for me since I only have to change my oil once a year. And yes, you have the oil analysis that shows that this is perfectly fine. Plus I don't throw out gallons of good oil a year.

You say you do lots of research.. Then you would know that in EVERY study shows that a K&N on average lets in more dirt than a foam or stock filter. You may not show much dirt in your oil, but if you ran one of the others you would show less dirt or oil.

You only selectivly use what research or facts you agree with and toss out the others.
-Chris

You and I hashed this out on the Tacoma board months ago and finally had to agree to disagree. I will encourage you to leave the K&N debate on that board as I'm sure the people here do not want to see it all over again.

I started doing analysis to prove that the K&N in MY Tacoma, in fact, was filtering. I had 13ppm (that's parts per MILLION) of dust in my oil after 5,000 miles of dusty conditions. That is "negligible" according to the analysis lab, so having even less was not a concern. SO, let's drop the K&N debate never to discuss it again, we're talking about oil here .

Second, actually you never sent me a 25,000 mile analysis, but I doubt it would be "OK". The Analysis you did send me with a mere 11,000 miles on it was borderline for an oil that is advertised to go for 25,000 miles or more (Amsoil) . Your nitration level was already at 37% which is close to being too high. The comments on your analysis also stated this. Amsoil oil may be ok for 25,000 miles in certain vehicles, but obviously not for the 3.4L Tacoma motor. Many others who had their oil tested on the Tacoma had similar results. 16,000 miles ended up being the "usual" max life of the Amsoil oil on that 3.4L motor. To me that DOES NOT justify the $9.00 a quart for the oil, especially since the 3.4L holds 5.5 Quarts, not to mention whatever you have to add when doing the filter changes PLUS the cost of the premium filter.

I'm going to be testing my oil in the new Xterra. Every engine manufacturer will be different. Once I have some numbers on the Xterra I'll post them here. The main thing on the Xterra, is that oil changes are a MUCH easier job. The oil filter is very simple to get to and is actually mounted in such a way that spillage will be nill.

For those that want to take a look at the actual oil analysis I have posted may do so HERE

Toy4x4-
Yes, I know we've been through this before. You know my results are not typical of any other person on ttora as I don't think anybody on that board drives as hard as me or constantly sand drags his truck for hours every other weekend. I would also say that my truck sees more offroad miles per 100,000 miles than anybody else on that board.

As for K&N, I didn't state you wern't in the safe zone for your driving conditions. I just said that the number would have been lower than it was if you had ran a different type of air filter.

For many though in offroad conditions you ought to state that many a person has found that K&N filtering has not been up to snuff.
-Chris

Well, another guy sent me a report for Amsoil oil with only 16,000 miles on the oil. His needed changing, so I don't think it's your driving style, but more the engine in question.

I think the K&N filtering has more to do with quality control on the gasket than the filter media itself. I never saw a spec of dust behind my filter even after a serious run at the tail end of a group on a VERY dusty gravel road. I was fortuneate enough to have a tight seal. Many others I know were not so fortuneate and did find dust behind their filters.

Do you know if there is an Amsoil filter for the Xterra available? I'm wanting one of those since it is an excellent compromise of filtering ability and performance AND is cheaper than the K&N. I don't think the "seal" on the Xterra air box will be an issue as it was on the Tacoma due to the Xterra's air box design, so the K&N will likely work fine on the Xterra, but I'd rather not spend so much on it.

I can say without a doubt that you do spend more time in the sand than anyone I know. Two (or more) broken engine mounts speak of your driving style . You obviously push things to their limits.

Toy4x4-
In the future I plan on buying a used baja race truck and doing that. Probably be 2 years down the road or so, but it's not really a question of 'if', but moreso 'when' I get around to start racing as a side sport.

As for K&N and Xterra.. go look, They probably make one. As for me, i have ideas of another TShirt 'prefilter' before my amsoil air filter; this sand really is annoying.
-Chris

As to the K&N and X question, they are finishing up the intake system for the S/C models right now. I just talked to the R&D guys the other day and after the S/C is done they are going to use both my 01 X and 01 Frontier to make the intake for the naturaly asperated models. I plan on posting the item # as soon as all the work is done.

You off roader types should be careful when running these types of intake systems. A buddy of mine recently threw a rod in his 2000 Tacoma due to mud getting sucked in through his K&N intake system.

I think the repair bill was somewhere in the $6,000 ball park.

I'd also like to add that on tacomas, even though the K&N intake sounds cool, dyno runs have proven that the K&N intake systems actually shows LOSSES over the stock air box.
-Chris

I have done my fair share of laboratory oil testing. The best oil that I ever tested was from a small company in Indianapolis, Indiana (D-A Lubricants Co.) So.....what makes for a good engine oil? Surprisingly, not lubricity! If you want to really extend that engine life, look for an oil that quickly neutralizes acids from the combustion process. Synthetics are a waste of time unless you have a high compression engine that creates excessive shear stresses. For the average person, the best compromise is Castroil (I'm not sure of the spelling) Castroil does have the acid neutralizers, but, unlike D-A Lubricants they don't have the little chemical hooks that keep the neutralizers in suspension and therefore increase the probability of collision between acid and the neutralizer.