Assuming you're talking 350k-400k kilometers, then we're talking about the same lifespan, and I don't doubt you for a second. My point isn't that changing your oil every 3000 miles is a necessity, it's that it isn't a very expensive thing to do and it sure can't hurt. In my experience, it helps. The cars I neglected in my youth (a Datsun B210, a '73 Olds Delta 88, and a Plymouth Colt, and a Plymouth Colt Vista (the last two were Mitsubishis, too, as were the cars T cited) all died early engine-related deaths (in miles, 90K, 130K, 95k, and 120k, respectively). I used to go up to 15k miles between changes because I was lazy and broke at times. Granted, they were all less-than-gently-used at the time I acquired them, too, except for the Colt Vista; the early demises may not necessarily be linked to my poor maintenance schedules. However, since then, I've been very careful with oil changes and it's paid off tremendously. Heck, maybe it's just coincidence, but I kind of doubt it. My two pro mechanic friends (one's the head mechanic at a very respected shop in the area, and the other's an independent European specialist.. the local Mercedes dealership calls HIM when they can't figure something out), both absolulute top notch guys in their field, are very adamant about 3000 mile oil changes. I believe them.

No arguments, T... I don't know enough personally to state scientific and physical reasons for my opinion. Just going by personal experience and people I know and trust. For me, frequent oil changes are worth it rather than saving $60 and hoping/trusting that it doesn't matter. That's all. If your experience is different and what you do works for you, there's certainly no reason for you to change either.

Best,

Barry

Tcoat... I got thinking some more. Another possible explanation is that you drive a LOT. That's good for a car. Few people put on the miles you do. 400K kilometers over 5-8 years is a lot different than, say, 200k miles over 30 years. Up until last year, my cars were made in 1981, 1988, 1993, and 1999. The '93 is gone now, as is the '99. The '81 Rabbit is off the road waiting for strut tower reconstruction, and the '88 560SL is about to go back on the road after sitting for seven months (and a grueling day in the garage yesterday). Those two get maybe 5000 miles a year, my main car (now the FR-S) gets about 15k a year, and my wife's SUV gets about 8K (all miles). Given the sporadic use (especially compared to your driving schedule), frequent short trips, and very infrequent long road trips for anything other than the FR-S (previously, the '93 325i), the 3000 mile oil change intervals make an increasing amount of sense. Your frequent long hauls probably contribute a great deal to your ability to stretch your oil change intervals.

Just thinkin' out loud..

Barry

I wish the dealership would learn to do that... sigh. The capacity is 5.5 quarts for the twins, and they put in 6 quarts both times I've had them do it; well OVER the top mark on the dipstick.

Can't hurt, true, but if you change every 3k miles (assuming 225,000 mile car lifetime) you'll make 75 oil changes, which at $60/change totals out to $4500. If you do 5k miles, which is still well within the recommended interval, the numbers over the same vehicle lifetime comes out to $2500. Yes, we are talking over multiple years of car life, but thats enough of a difference that I would say that it is actually a lot more expensive to do it every 3k than every 5k.

Second point, your engine-related deaths for sure were due to your "up to 15k" change interval.

Lastly, I'm willing to bet your mechanic buddies don't pay for oil changes. So of course they would recommend the most aggressive interval.

Yup,mine did when I was at about 5k.

I find it funny that for a crowd that swears by the owner's manual,this is one thing that they completely refuse to abide by. Obviously you should check you oil on a somewhat regular basis,depending on driving habits,but changing oil every 3k miles on this car is just throwing money away.

I remember when I bought my car,I would check the oil every once in a while,and every time,it was as golden as when I bought it.Even well after the mythical 3k miles,it looked like it was just changed the day before.Eventually,I change it at 7k because of the dealer sending me a notice,plus I had a coupon which came out to about $48.

The manual actually specifies 5.8 not 5.5

No arguments here on the math. 12K, 7.5K, 5k, 3K... the more frequently you do it, the more money you spend on oil changes. That's obvious. Finding the cost vs. return point based on your car and driving habits is the crux of the whole issue. For me, I aim for 3K. If I go a bit over, I don't worry. $2000 saved over what, for me, would be about 12-13 years, would be about $160/yr... less than what a lot of folks pay every month for cable. For me, it's worth it. That's all.

Well, not much in life is "for sure," but it's very likely it was a major contributing factor. Again, point granted. 15k, however, isn't much longer than the 12k that some car manufacturers and synthetic oil producers are recommending. I wasn't using synthetic back then, of course. Synthetic or dino, dirt is dirt, and today's engines are typically manufactured with much tighter tolerances than those of yesteryear... hence the increasing usage of lower viscosity oils. Heck, it's getting hard to even find 10w40 anymore.[/QUOTE]

You'd lose that bet. One's an independent, i.e., he is the owner and sole employee; who do you think buys the stuff in his garage? The other may get a break, but he buys all his parts, including maintenance supplies, and keeps a fully equipped two-bay garage on his own property for maintaining his own vehicles. Being an employee doesn't give you a license to steal from your employer, and both of my friends are unfailingly honest.

This is the internet. Opinions vary. Some are fact-based, some are emotion-based, and some are just stupid and/or irrational. Heck, there's probably at least a little of all of those in most opinions and I'm more than willing to admit there are in mine. I'm not suggesting I'm "right" and that aiming for 3000 mile oil changes is THE only thing to do. For me and my vehicles, it works and I'm willing to pay the extra few bucks a year. For others, maybe not. That's fine. I'm not arguing that point. You kind of struck a nerve with the insinuation that two excellent mechanics who would have no vested interest in getting me to change my oil frequently (they don't profit by it.. I buy my own stuff and change my own oil except for the FR-S/warranty reasons mentioned earlier in the thread) somehow get free oil changes because they're mechanics. Huh? I'm a musician.. do I get a free grand piano? Can I take the one home at the concert hall I occasionally play in?

Maybe I read too much into that.. sorry.. :)

Barry

Thanks. I was going by a post I had read on this forum (another thread, months ago) and hadn't checked the manual since I've had the dealer do them so far. I'm surprised, though.. they really overfilled it both times, more than 2/10 of a quart would seem to account for. Sorry about repeating bad info.. thanks again.

Barry

I usually drive mine 1-2 times / week so i usually go with mileage but i change oil once a year at least. if you feel this is right then do it. it's your money and time. better to change often than not. i change oil for all my cars between 7000 - 7500 mileage inverval with synthetic oil like mobil 1. i tried Pennzoil Ultra and couldnt tell damm difference and it was little more expensive than mobil 1 so i am sticking with mobil 1 now

Same here.

Why so many miles?

Now THAT's funny. If you do a used oil analysis, you'll see that regular Mobil 1 (not to be confused with Mobil, Alabama) can do well over 6k miles and Amsoil SS and M1 EP can go much farther.

Yes, you should probably the manufacturers recommendation while under warranty (although ask a dealer if they'll change the oil in a car that sat on their lot for a year), but to change it based in taste, feel, color, odor, engine sound, etc. is not based on fact.

There are plenty of uoa's on this forum and I'd recommend looking through them. Some have gone to 10k miles. Of course, you need to make sure your filter can last as long as the oil. If it's OEM, it can easily handle 6-7.5k miles.

I have 4 plants that I am responsible for spread 3 hours apart. I travel to all of them weekly. I get paid mileage though so actually make money while depreciating the value of the car.

I've seen them all and do not dispute. I won't go into my resume but trust me, I'm the last person you would think to go against all the published material. Still, I cannot ignore my gut so when I begin to feel the extra NVH, I go for it.

Maybe I'll go back to just changing the filter early.