How often do you change your oil?

[Eric]

Just a survey... .

I change the oil and filter in my vehicles as follows:

* Lightly driven/antiques -

Since these don't see more than about 1,500 miles annually (sometimes less than 500) I go by time interval instead. I do them twice a year, in spring and fall - always using top quality synthetic and premium filters.

* "Daily driven" -

Both trucks get their oil and filter changed every 3,000 miles, always with high quality synthetic and premium filters. This may be on the over-cautious side but I know it can't hurt and I suspect it might be part of the reason that my trucks both run like new - including the '98 with close to 120,000 miles on it. (The engine still pulls appx. 19 inches of vacuum at idle, indicating a very "tight" engine.)

* Tractors/mowers/power equipment -

Once a year - at the end of the season (fall) before they go into a period of several months of disuse. (I do start each one once every four weeks or so during the off season and let it run for about 15 minutes.) My theory here is that it's good to get the old, dirty oil out at the end of the season rather than leave it sitting in the sump until spring. Fresh oil in them before storage helps keep things clean and well-lubed, so the equipment will be easier-starting (and wear less) come spring.

What do you do?

[DonTom]

Just a survey... .

I change the oil and filter in my vehicles as follows:

* Lightly driven/antiques -

Since these don't see more than about 1,500 miles annually (sometimes less than 500) I go by time interval instead. I do them twice a year, in spring and fall - always using top quality synthetic and premium filters.

* "Daily driven" -

Both trucks get their oil and filter changed every 3,000 miles, always with high quality synthetic and premium filters. This may be on the over-cautious side but I know it can't hurt and I suspect it might be part of the reason that my trucks both run like new - including the '98 with close to 120,000 miles on it. (The engine still pulls appx. 19 inches of vacuum at idle, indicating a very "tight" engine.)

What do you do?

IMAO, you change oil way too often! I change engine oil no more often than every six months and with vehicles that are used less than a thousand miles per year, I change engine oil once per year.

And don't be so sure it cannot hurt. I have heard "theories" that the fresh additives (as in new engine oil) clean parts a lot better. This could mean more unnecessary wear on the engine parts. So perhaps you get more wear of engine parts by changing the oil too often!

And why waste your money on synthetic engine oils on vehicles that you only use 500 miles per year?

-Don- SF, CA

[Eric]

IMAO, you change oil way too often! I change engine oil no more often than every six months and with vehicles that are used less than a thousand miles per year, I change engine oil once per year.

And don't be so sure it cannot hurt. I have heard "theories" that the fresh additives (as in new engine oil) clean parts a lot better. This could mean more unnecessary wear on the engine parts. So perhaps you get more wear of engine parts by changing the oil too often!

And why waste your money on synthetic engine oils on vehicles that you only use 500 miles per year?

-Don- SF, CA

I use synthetics, in part, because of their objectively superior cold start/high temperature protection. We live in an area that often has severe winters, with temps. in the single digits (unike temperate CA!). Synthetic oil has much better flow characteristics at these temps than conventional oil. And synthetics offer superior protection at the opposite end of the temperature scale, too.

With an antique vehicle - with an engine that has been out of production for more than 30 years now and which would be very expensive to replace - I think the small expense associated with a twice-yearly oil and filter change (about $40 per) is well worth the cost.

Ditto the daily-drivers. I prefer to "invest" as little as possible in my transporation modules and if I get 200,000 miles out of a truck I bought for under $10k then I figure having spent an extra $200 or so over a ten year period for oil/filters is, once again, money well-spent!

[misterdecibel]

I follow the recommendations in the owner's manual. For my car, that means the first two oil changes were at 5K and 10K, after that the interval is every 10K miles.

I can't find the link now, but I saw a test online somewhere where they were running, I think, a 2002 Z28 on "Green German Syntec", and taking samples to the lab at regular intervals. It was finally determined that the car was ready for an oil change at around 13.5K, and the filter was still good but they changed it anyway. I don't remember if the filter was AC/Delco, or aftermarket.

[Mase]

Just a survey... .

I change the oil and filter in my vehicles as follows:

* Lightly driven/antiques -

Since these don't see more than about 1,500 miles annually (sometimes less than 500) I go by time interval instead. I do them twice a year, in spring and fall - always using top quality synthetic and premium filters.

* "Daily driven" -

Both trucks get their oil and filter changed every 3,000 miles, always with high quality synthetic and premium filters. This may be on the over-cautious side but I know it can't hurt and I suspect it might be part of the reason that my trucks both run like new - including the '98 with close to 120,000 miles on it. (The engine still pulls appx. 19 inches of vacuum at idle, indicating a very "tight" engine.)

* Tractors/mowers/power equipment -

Once a year - at the end of the season (fall) before they go into a period of several months of disuse. (I do start each one once every four weeks or so during the off season and let it run for about 15 minutes.) My theory here is that it's good to get the old, dirty oil out at the end of the season rather than leave it sitting in the sump until spring. Fresh oil in them before storage helps keep things clean and well-lubed, so the equipment will be easier-starting (and wear less) come spring.

What do you do?

When I was driving `20k miles a year I did it every 3000 miles without regard to months. Now that I am driving only around 4-5k miles a year I change my oil every 3000 miles or every 6 months or so, and for years and years I have been adding a bottle of STP to the oil at each change.
I usually use Castrol 10w-40.

[DonTom]

I have been adding a bottle of STP to the oil at each change.

At best, that's a big waste of money. There's no evidence that STP is helpful to anything.

-Don- SSF, CA

[dom]

Oil change break down:

• atv - every third ride
• mower & pressure washer- once a year
• toy car - twice a year
• daily driver - every two months (about 3,000 miles)
• wife's truck - every four months (regardless of miles, very little though)
• motorcycle - twice a year

I do use an additive in one of my vehicles. I use Slick-50 in my motorcycle. Don't know why, but I think it likes it. I only use it in the summer.

[Eric]

Oil change break down:

• atv - every third ride
• mower & pressure washer- once a year
• toy car - twice a year
• daily driver - every two months (about 3,000 miles)
• wife's truck - every four months (regardless of miles, very little though)
• motorcycle - twice a year

I do use an additive in one of my vehicles. I use Slick-50 in my motorcycle. Don't know why, but I think it likes it. I only use it in the summer.

The only additive I use is a bottle of ZDDP additive when I change the oil in the Trans Am. This additive contains the zinc and other anti-friction additives that used to be present in most high-grade motor oils but which have been removed or greatly reduced due to emissions reasons. For modern engines, it's a non-issue as they no longer use flat tappet camshafts. But if you have an older vehicle that does have an engine with a flat tappet cam, adding a bottle of ZDDP is probably a good idea. Camshaft failure is something you don't want to deal with - especially if it can be avoided by using a bottle of $8 additive twice a year!

[Ken]

At best, that's a big waste of money. There's no evidence that STP is helpful to anything.

-Don- SSF, CA

Not too sure about that, Don. Back in the days when I used to tune engines for autocross, rallying and fast road use I always recommended using Duckhams Q20/50 (the oil of choice in those days) with a can of STP. Hustling along, in my souped up Cooper, I heard a 'clunk' and I thought the fan belt had broken. To keep cooling air going through the radiator I drove the last twenty miles at quite illegal speeds. The only thing that showed on the gauges was a slight drop in temperature. It was next day that I found that the 'clunk' was a disintegrating fan blade taking the bottom out of the rad. Twenty miles, high speed, no water - NO DAMAGE!, I reckon that STP did what it said on the tin. (The drop in temp shown on the gauge was due to the fact that there was no water round the bulb and it was picking up heat from the head itself via the sensor body.)

Ken.

[Eric]

Not too sure about that, Don. Back in the days when I used to tune engines for autocross, rallying and fast road use I always recommended using Duckhams Q20/50 (the oil of choice in those days) with a can of STP. Hustling along, in my souped up Cooper, I heard a 'clunk' and I thought the fan belt had broken. To keep cooling air going through the radiator I drove the last twenty miles at quite illegal speeds. The only thing that showed on the gauges was a slight drop in temperature. It was next day that I found that the 'clunk' was a disintegrating fan blade taking the bottom out of the rad. Twenty miles, high speed, no water - NO DAMAGE!, I reckon that STP did what it said on the tin. (The drop in temp shown on the gauge was due to the fact that there was no water round the bulb and it was picking up heat from the head itself via the sensor body.)

Ken.

I recall NASCAR teams used to use STP as a break-in additive as well as a general additive for high-load/high-heat protection. It may be that modern oils - which are vastly superior to what was commonly in use 20 or 30 years ago - don't need the extra additives in STP. But I don't see how it can hurt - and my default setting on this stuff is that it's preferable to err on the side of caution and even "waste" a few bucks on something that may be overkill rather than go with the bare minimums and risk excess/premature wear (which costs a helluva lot more than a can of additive - or even a case of it!)

I also changeout the lube in the transmissions/transaxles and rear axles of my vehicles at half the intervals recommended by the manufacturer. Overkill? Perhaps. But I have never had a transmission fail on me and I figure spending the $40-$60 it costs to change the lube is a solid investment vs. the $1,500-$2,500 a new transmission/transaxle or rear axle would cost me.

Plus, the cars drive noticeably more smoothly and I am confident I am getting the best possible gas mileage (through reduced friction), too.

[Ken]

I recall NASCAR teams used to use STP as a break-in additive as well as a general additive for high-load/high-heat protection. It may be that modern oils - which are vastly superior to what was commonly in use 20 or 30 years ago - don't need the extra additives in STP. But I don't see how it can hurt - and my default setting on this stuff is that it's preferable to err on the side of caution and even "waste" a few bucks on something that may be overkill rather than go with the bare minimums and risk excess/premature wear (which costs a helluva lot more than a can of additive - or even a case of it!)

I also changeout the lube in the transmissions/transaxles and rear axles of my vehicles at half the intervals recommended by the manufacturer. Overkill? Perhaps. But I have never had a transmission fail on me and I figure spending the $40-$60 it costs to change the lube is a solid investment vs. the $1,500-$2,500 a new transmission/transaxle or rear axle would cost me.

Plus, the cars drive noticeably more smoothly and I am confident I am getting the best possible gas mileage (through reduced friction), too.

I'm with you all the way on this one, Eric.

Ken.

[DonTom]

"I also changeout the lube in the transmissions/transaxles and rear axles of my vehicles at half the intervals recommended by the manufacturer. Overkill?"

I do the opposite. Change it half as often, if even that. Often trannys start to leak right after a fluid change and you could be better off without the change. I just check the fluids once in a while and if it looks okay, I usually forget about it. If I think something doesn't look right or feel right (or sound right, as in my Jeep) I will then change the tranny fluid and diff gear oil / transfer box gear oil (And that did get rid of the noise when steering at very slow speeds).

If you owned as many vehicles as I did, you would understand why I don't change fluids more often than I think is really necessary. Oils last several times as long these days as they used to.

I rarely have any tranny problems but when I do, it's usually about time to junk the vehicle anyway.

-Don-

[DonTom]

"The only additive I use is a bottle of ZDDP additive when I change the oil in the Trans Am."

Now that I agree with for the older engines. Mainly because they were designed for it to begin with and the stuff was removed later.

BTW, the closest I have seen any owner's manual recommend a synthetic engine oil (or even any engine oil additive) in any vehicle I have owned is in my 2000 RV (7.4L). It said "if the outside temperature is below -20F, you MIGHT want to CONSIDER using a synthetic engine oil".

As you know, I have never been big on synthetic engine oils (synthetic gear oils is a different subject) or any additives in modern engines unless the owner's manual says to use them.

I think I got that was from my 1971 BMW motorcycle. It clearly said in the owner's manual that adding any additives to the gasoline or engine oil for any reason will void all warranties--no exceptions.

-Don- SF, CA

[Eric]

"I also changeout the lube in the transmissions/transaxles and rear axles of my vehicles at half the intervals recommended by the manufacturer. Overkill?"

I do the opposite. Change it half as often, if even that. Often trannys start to leak right after a fluid change and you could be better off without the change. I just check the fluids once in a while and if it looks okay, I usually forget about it. If I think something doesn't look right or feel right (or sound right, as in my Jeep) I will then change the tranny fluid and diff gear oil / transfer box gear oil (And that did get rid of the noise when steering at very slow speeds).

If you owned as many vehicles as I did, you would understand why I don't change fluids more often than I think is really necessary. Oils last several times as long these days as they used to.

I rarely have any tranny problems but when I do, it's usually about time to junk the vehicle anyway.

-Don-

When I drain the lube in manual transmissions/rear axles after appx. 30,000 miles, the lube is noticeably dirty and usually there's some sludge (including fine metal shavings) on the magnetic drain plug. I don't see how it wouldn't be of benefit to drain out the contaminated/fouled fluid (and with it, the abrasive particles held in suspension) and refill the the thing with fresh lube, free of gunk - and with fresh additives, etc. I know for sure the transmission shifts better and makes less noise - especially noticeable on cold days.

My understanding is that regular fluid/filter changes with automatics are even more important. One reason being that the filters will eventually become clogged (or flow restricted) if you leave them in there too long. Even small particles of grit, etc. circulating through the tiny orifices of an automatic transmission can cause major problems. Also, the additives in the fluid break down, just like the additives in motor oil.

Why risk such problems over a relatively minor/cheap/easy-to-do (or have done) service?