Engine oil

[rgrugg]

If you've switched from regular engine oil to synthetic have you noticed any improvement in performance or extended engine life? Trying to decide if I want to make the switch. Any comments will be appreciated. Thanks

[Mike Magee]

I think any anectodal evidence about longevity would be of little value, considering how long engines last nowadays. As for performance, I have noticed no difference.

I am of the opinion, based upon reading, that engineered-from-scratch full synthetics will resist long chain molecule breakdown far better than refined petroleum oil. In other words, dino oil will thin out faster. But it seems that this breakdown is not significant for the first 4,000 or 5,000 miles anyway. So if one changes the oil faithfully at intervals of 5000 or less, it probably doesn't make much difference.

I have run some Mobil 1 and Amsoil for extended intervals up to 15,000 miles, mainly in my Mercury. 180K miles, engine still doesn't use more oil than when new. My Toyota oil filter size and type isn't conducive to long intervals, though.

[mary and bob]

I stay with one brand of regular oil and do frequent oil changes, between 2000 and 3000 miles. One of my tractors I bought new in 1968, changed oil more often than recommended, and it uses no oil yet. I've always understood that if you are going to use synthetic oil you should do so from day one when the vehicle was new. When I worked for a nationwide truck leasing company we used regular engine oil but synthetic gear oil. If you haven't been using synthetic, I wouldn't switch now.

[Darwin Maring]

If you wait to long and the engine is already worn then the synthetic aint gonna help. The + side of the synthetic is that all molecules are the same size so it helps to maintain the same protection around the parts to keep them from having metal to metal contact

On high mileage engines try Restore. It has been around for a long time and magazines that test stuff like this state it works.
Restore USA - Engine Restorer

[steve dunham]

Originally Posted by Mike Magee

I think any anectodal evidence about longevity would be of little value, considering how long engines last nowadays. As for performance, I have noticed no difference.

I am of the opinion, based upon reading, that engineered-from-scratch full synthetics will resist long chain molecule breakdown far better than refined petroleum oil. In other words, dino oil will thin out faster. But it seems that this breakdown is not significant for the first 4,000 or 5,000 miles anyway. So if one changes the oil faithfully at intervals of 5000 or less, it probably doesn't make much difference.

I have run some Mobil 1 and Amsoil for extended intervals up to 15,000 miles, mainly in my Mercury. 180K miles, engine still doesn't use more oil than when new. My Toyota oil filter size and type isn't conducive to long intervals, though.

Mike :When you run synthetic oil for a 15000 mile OCI do you change the oil filter at 7500 miles ?. From what I have read the oil will last for 15000 miles but the oil filters are not designed for 15000 miles and end up going into bypass long before you change oil . NAPA told me that their NAPA Gold filter (Wix ) is not rated for 15000 miles . This may be a good question for Floyd

[Bob Miller]

I have run Mobil-1 exclusively in my 2003 GMC Sonoma and, at 158,000 miles do not use a drop of oil nor do I have any leaks. I started with synthetic simply because I would always forget to get an oil change every 3-5k miles. I usually run to about 7.5 - 8k miles between changes and have been satisfied with the extra expense.

But don't expect to get any better performance, economy or more admiring stares just because you use synthetic oil.

[Raz]

Manufacturers oil change intervales seem to be getting longer and oil filters do seem smaller. Our Subaru has the latest version of their boxer engine. It uses 0W20 synthetic changed every 7500 miles. Also the oil plug uses a crush washer and the oil filter is right under the hood, both *nice features. Raz

[SilverGhost]

I have an oil filter that is clearly labeled "30,000KM or 2 years" The manufacture of the car also recommends 10k miles (that's the filter for said car). The oil change analysis indicates 15k miles is correct change interval for my car.

The old recommendation for not switching to synthetics was the molecule chains have an easier time leaking out and clean out the crude left behind (and sealing to some extent) by the dino based oils. So on a really high mileage car with worn seals the gunk left behind by the dino oil is keeping it from leaking. Switch to synthetic oil and there is high probability of the gunk getting washed out and oil leaking from the newly exposed seal defects.

My car is tough on oil. Mobile One won't cut it. MB 229.1(?) spec oil or VW 505.01 spec oil will put up with a lot and last a long time. Costs more so you have to leave it in a long time to make the ROI work out.

Jason

[Francesca Knowles]

Reliable, independent evidence that "synthetic oil" is measurably better for an engine in the long run is very hard to find. And it's definitely harder on the pocketbook!

Francesca

[steve dunham]

Originally Posted by Francesca Knowles

Reliable, independent evidence that "synthetic oil" is measurably better for an engine in the long run is very hard to find. And it's definitely harder on the pocketbook!

Francesca

I have purchased Quaker State, Mobil 1 , Penzoil Platinum, and Napa , full synthetic oil for as low as $2.29/ Quart . Not much difference in cost than Dino or synthetic blend oil ( I realize these are not considerd "Full Synthetics by the Amzoil crowd)

[David B.]

I became a believer in the early 1960's when STP was used by a friend of my older brother (he managed a dairy truck fleet). He set up half his fleet of refrigerator trucks with, and half without STP. The normal need for scheduled teardown/rebuild doubled. I then was turned onto Amsoil for my brand new 1979 Diesel Rabbit manual transmission, which was impossible to shift in below zero Michigan weather until after an idling engine would warm it up. The Amsoil synthetic allowed immediate cold shifting. I've been using synthetics throughout (diff/trans/transfer case/power steering) and have noticed great improvements in all, especially in extreme high or low temps (I now live in Arizona). I always keep vehicles well over 100,000 miles.

[Bob Miller]

What is the vehicle that it "Tough on Oil" and why? I think that I may want to avoid that one.....

Originally Posted by SilverGhost

I have an oil filter that is clearly labeled "30,000KM or 2 years" The manufacture of the car also recommends 10k miles (that's the filter for said car). The oil change analysis indicates 15k miles is correct change interval for my car.

The old recommendation for not switching to synthetics was the molecule chains have an easier time leaking out and clean out the crude left behind (and sealing to some extent) by the dino based oils. So on a really high mileage car with worn seals the gunk left behind by the dino oil is keeping it from leaking. Switch to synthetic oil and there is high probability of the gunk getting washed out and oil leaking from the newly exposed seal defects.

My car is tough on oil. Mobile One won't cut it. MB 229.1(?) spec oil or VW 505.01 spec oil will put up with a lot and last a long time. Costs more so you have to leave it in a long time to make the ROI work out.

Jason

[SilverGhost]

The cam driven injectors necessitated a change in cam lobe size to make room. A combination of that and less than ideal oil flow to the bearings, lifters, and lobes can lead to cam lobes wearing through the top of the lifters. There was also a rumor that there was some issues with metallurgy in the cam that contributed to premature cam wear.

The solution, from the very start, was a high film strength oil that would keep the cams adequately lubricated. This applies to Pump Duese version of the TDI that Volkswagen makes.

Then there was/is the 1.8T in the A4 Audi and Passat VW. That engine would still sludge up on Mobil One, but not VW spec oil.

Neither engine is made anymore. And both have shown the ability to go over 300k miles if taken care of. I like mine and just figure pricy oil change is cost of admission.

Jason

[floyd]

Originally Posted by steve dunham

Mike :When you run synthetic oil for a 15000 mile OCI do you change the oil filter at 7500 miles ?. From what I have read the oil will last for 15000 miles but the oil filters are not designed for 15000 miles and end up going into bypass long before you change oil . NAPA told me that their NAPA Gold filter (Wix ) is not rated for 15000 miles . This may be a good question for Floyd

I have been asked this question many times...
My response is another question...
"What sort of underwear do you wear?"
The response is usually..."!!????!!
The question appears to be a non sequitur until I explain...
"Boxers, breifs, silk, or cotton, They all get soiled and must be changed frequently.
Use a good quality motor oil which meets the required SAE spec for the application and change it often. I change my oil at 3000miles and my underwear daily. Some folks are comfortable with going twice as far...
Beyond that, there starts to be consequences.

[Darwin Maring]

2007 Silverado: Change oil Once a year or when the readout tells you to. Whichever comes first.

[Mike Magee]

Originally Posted by steve dunham

Mike :When you run synthetic oil for a 15000 mile OCI do you change the oil filter at 7500 miles ?. From what I have read the oil will last for 15000 miles but the oil filters are not designed for 15000 miles and end up going into bypass long before you change oil . NAPA told me that their NAPA Gold filter (Wix ) is not rated for 15000 miles . This may be a good question for Floyd

Yes, unless a high capacity filter of some sort is available, it has to be changed out midway. My Toyota's filter is one I absolutely hate changing (it is a pleated filter inside a permanent aluminum housing that can be a bear to remove sometimes), thus the change in my practices.

One more thing I recall reading: synthetics tend to keep rings in better shape (staying swelled rather than shrinking with age as with ordinary oil).

[Brian B-P]

What Mike said

I use synthetics, but for less viscosity change with temperature, not in pursuit of longer oil change intervals or reduced engine friction.

[Hambone]

all my vehicles get mobile 0w-30 changed spring/fall, synthetics in differentials if they have them. Only problem I ever had was when i first got married and my wife ran a 1980 pinto 4 quarts low of oil, and that was a fatal problem, in my mind when you drive something you check the oil....her reply to that was 'why do you think I got married!!"

[Daniel A.]

The problem with switching is the tolerances that synthetic oil runs at is much tighter than regular oil.

If the car or truck were new than yes running synthetic will extend engine life.
On a used car or truck you likely won't see a gain in engine life but synthetic will tolerate higher temps before breaking down.

[Bill in Pittsburgh]

Bob & Grace, Seeing that you are from Michigan (rust belt) and assuming that you don't drive like a teenager that thinks he/she is on a drag strip, it is unlikely synthetic oil is going to make a difference in your engine life. Your vehicle will probably rust away around your engine and when it eventually goes to a scrap yard, your engine will probably be one of the few things left that is still good.