How long between synthetic oil change?

Yup just the same as dino oil --- although I'd go to higher of the mileage 5k vice 3k. Isn't it actually 7.5k? Hope yours doesn't start leaking like mine did! Switched back to

10w30 and no leaks. IMHO - not worth the extra 3x the cost.

eric, i do the oil (mobil 1) once a year and filter every 3k (and top off what i lose from the filter change). i've done this for years and never had a problem in any of my cars. my saab 900 with 185k miles doesn't leak or burn a drop! it turns out that the average oil molecule isn't in my engine for more than 15k miles. if you buy a new bimmer or mercedes or audi, you get "free" oil changes ever year or

12k miles which ever comes first. they also use synthetic (i think mercedes uses mobil 1) but don't change the filter every 3k, so i figure i'm doing better than they are.

mike

Eric, you're good for at least the full oil drain interval shown in your owner's manual. Ken

That is A1 advice. Anything more is at the owners risk and should only be done with an appreciation of the risk verses benefit.

Huw

Oil changes for these cars are NOT at 12k miles. Depending on driving conditions and the engines fitted, the oil changes can vary from 9000 miles to near enough 30,000 miles/two years [in the case of some VW/Audi] in ideal conditions. The oil is NOT standard synthetic and the filtration is specially designed. Furthermore the oil and car is dynamically monitored and the interval adjusted accordingly. All *you* do is change the filter and use a standard synthetic which may not even meet ACEA A2. Please make sure your oil does, although you seem to be on the safe side of intervals according to your post. The 'once per year' caveat is very important.

Huw

I have a 1993 Toy PU 4 x 4 extra cab with 105K miles and I switched to Mobil

1 at 42K.

Since then, I change the oil at 7500 mile intervals with Purolator Pure 1 oil filter and the truck still runs very well.

Anything less than 7500 mile intervals is a plus, but IMHO, a waste of a good oil and money

Climb14er Denver, CO

I've managed to get high mileage on vehicles using dino oil changed at

3000~5000 mile intervals. Based on my own experience, limited as it is, there's no real benefit to the more expensive synthetics *except* the ability to run higher mileage between changes.

My wife and I both run a lot of miles in our businesses. I spent an inordinate amount of time changing oil and trying to get rid of it -- for me, getting rid of the old stuff was more inconvenient than changing it.

For that reason, I've switched to Amsoil oil and filters and have stretched the change intervals to whatever the manufacturer recommends. Amsoil actually recommends much longer intervals, but I just can't do it.

You really don't need to change Amsoil or other good synthetics that often. They have been reccomending 25,000 or once a year since 1972. Check out how often Europeans change the oil in their cars. Also, if you by a BMW here in the States right now in the manual it sais to change the oil every 15,000 miles or once a year because it is factory filled with synthetic. Every 3,000 miles is a joke perpetrated on the American Public by the Petroleum Industry. If it helps you sleep at night than change your oil as often as you would like. Sleep is pretty important.

David Reid

3,000 mile changes are a waste with the current conventional oils, and a joke if you use synthetics. But even if you use a synthetic oil if you don't change your oil within the minimum service intervals stated in the warranty (usually 7,500 miles or once a year) or don't use the proper weight oil that is properly certified by an independent laboratory to meet the car manufacturer's standards (and they want to be hard-nosed about it) your factory warranty is null and void.

The last time I looked into it, Amsoil only makes one line of oil that is properly API certified to meet the car maker's requirements - use the others that aren't API certified, and it's an instant warranty killer.

For most cars, remanufactured engines with installation start at $3,000 and up. Way up if you want brand new and not rebuilt.

The oil manufacturer can recommend any non-certified oil or extended oil change schedule they want - 15,000 miles, 25,000 miles, or more, but they can't change the terms of your vehicle warranty.

Unless the oil manufacturer is willing to pay all repairs that the factory warranty won't (don't hold your breath waiting for the check) Do Not stretch your oil change interval past the car manufacturer's intervals. Oil is cheaper than a new engine.

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I go 5,000 miles on Mobile 1 in my Sequoia, with a new filter each time. I think this is more than I need, but gives me some slack if I can't get to it right away. I think the 7,500 interval recommended by my owner's manual is fine, but really, even synthetic oil is cheap for the job it's doing. I buy 5qt jugs from Walmart at $17 or $18 a jug.

6.5 qts and a filter only cost me $27.50 or so if I do it myself.

For a real-world, lab analysis-backed, unbiased testing, check this site:

They've tested Mobile 1 out to 18,000 miles. Amsoil is next.

I agree, Bruce. I'm changing both cars well before the 7500 miles recommended by the manufacturer.

FWIW, I'm using Amsoil 5w30 which carries a statement on the label that it "meets or exceeds" the following certifications:

API SL, SH, SJ, CF ILSAC GF-1, GF-2, GF-3 Chrysler MS 6395 H Ford WSS M2C-153G GM 4718-M VW 500.00, 501.01, and 505.00 Energy Conserving II Mercedes-Benz AG 226.1

All these posts seem to imply that the only consideration for oil change intervals is the state of the oil. I propose that this is only an excuse to have a vehicle checked over for many different maintenance items. I choose to have my vehicles maintenanced evey 5000 miles. This includes rotating tires, lube all items listed in owners manual, top off all fluids, adjust tire pressure, inspect belts, hoses, brakes, lights, wipers, drive train etc.... I have this maintenance done at the same SERVICE station every time. I don't use quickie services. I have found that the extra expense of having a truely qualified and experianced person do my work is money well spent. Just my thoughts on the topic. Oh, yeah synthetic oil is a waste of money when changing oil on such a regular basis.

Don't you check most of these, certainly the safety related ones, regularly between services?

I have this maintenance done at the same SERVICE station every

I tend to agree with the latter but am doubtful about the former but it seems you have been lucky with your dealer. I have found that qualifications are not a good indicator of aptitude or ability in this area. Main dealers tend to employ monkeys to perform scheduled services so the smaller outfit gets my vote as long as they have a good reputation. Reputation is my yardstick, not qualification.

Huw

I was with you 100% until that last statement. If you're running regular dino, it has disintegrated significantly before you hit 5000 miles.

2000 miles would be a lot more like it for non-synthetic oils. 5000 miles is about as far as I care to push full-synthetics, but that reduces its cost significantly compared to dino at 2000 miles. Anyway, it's money well spent.

Tom S

FWIW, I had a sample of oil tested that I'd run in my motorcycle for

2500 miles. The 10w40 petroleum oil that I started with had sheared to a 20 weight. I know that automobile engines don't shear like bikes do, but it was still enough to make me want to switch to a full synth for more than 3000 mile drain intervals.

For myself I go to 10K miles with my '97 4-Runner (V-6) for the oil and filter change. After running the milage up to 5000 miles I started using Mobil 1 and

5000 oil change intervals. At about 100K miles I had the oil tested and the testing company recommended upping the interval. So I bumped it up to 7500 miles. I felt uncomfortable running the interval up to 7500. I sent in another sample for analysis and again they recommenced upping the interval. I didn't right away. I went through another oil change or two before I tried a 10,000 mile interval. I sent in a sample of the oil after 10,000 miles and again the oil was in good enough condition for more milage. I had the oil analyzed during winter and summer. Since it gets dusty during summer I wanted to see if the particulate matter would get too high during summer. It didn't so I now I keep my intervals to 10,000 miles. I do use the 4-Runner as my daily commuter. 25 miles of one way highway driving. So I know I am driving under ideal conditions. The oil is always heated up enough to rid the oil of the water contamination. So bump up the milage intervals and have the oil analyzed.

time... syn

That's told me! LOL. What quantities of additives are in which oils and why do they 'wear out' at 3001 miles?

Huw