Switching from regular to synthetic oil?

java230 wrote:

Bobzilla wrote: Oil analysis is a beautiful thing. First, to the OP.... change it, check it regularly. It's not uncommon for hte first change or two on an older engine to burn a little bit depending on it's history. The extra detergents etc tend to clean things a little and then burn it off. Not a big deal.... Since OA is now what I do daily, I started testing mine to see if I was wasting it or not. I've been running Wal-Mart "Full Synthetic" for years in all of our vehicles. I adhered to the 5k OCI's on the cars, and letting the truck's OLM tell me with it. At 5k, the oil was in extremely good shape. So, after last winter, I changed it before the MAth Tour at the Corvette Museum, then ran it the entire year (12 events total, plus daily driving). Tested it at 3k, 6k and then at 9500. Still no wear. No contamination to speak of (a bit of fuel dilution, but that was expected). Could have stretched it a little farther to about 12k and still been fine. I wussed out and changed it. So, if a $17 jug of "synthetic" oil can last 10k miles with the abuse I put it through, I know that the "top tier" fluids will last much longer. Hell, I see it daily.

Did you change filters at all during that time? I get a little nervous as mine is very dark after 7500, but that's when the light comes on in my truck.

it's been my understanding that dark just means the oil is doing it's job ... as for changing out the filter ... for some reason I hadn't thought about that ... had not even considered ... now you're making think about something new

""

Bobzilla wrote:

java230 wrote:

Bobzilla wrote: Oil analysis is a beautiful thing. First, to the OP.... change it, check it regularly. It's not uncommon for hte first change or two on an older engine to burn a little bit depending on it's history. The extra detergents etc tend to clean things a little and then burn it off. Not a big deal.... Since OA is now what I do daily, I started testing mine to see if I was wasting it or not. I've been running Wal-Mart "Full Synthetic" for years in all of our vehicles. I adhered to the 5k OCI's on the cars, and letting the truck's OLM tell me with it. At 5k, the oil was in extremely good shape. So, after last winter, I changed it before the MAth Tour at the Corvette Museum, then ran it the entire year (12 events total, plus daily driving). Tested it at 3k, 6k and then at 9500. Still no wear. No contamination to speak of (a bit of fuel dilution, but that was expected). Could have stretched it a little farther to about 12k and still been fine. I wussed out and changed it. So, if a $17 jug of "synthetic" oil can last 10k miles with the abuse I put it through, I know that the "top tier" fluids will last much longer. Hell, I see it daily.

Did you change filters at all during that time? I get a little nervous as mine is very dark after 7500, but that's when the light comes on in my truck.

No filter changes, no addition to the oil (car just doesn't burn it. At 9500+ miles it was within a half quart of the full mark). OIl color is one of those things people put a lot of faith into when it really means nothing. We test all sorts of things for all types of oils and not a single one involves a lab tech looking at the oil and making any determination whatsoever. OIl getting dark means it's doing it's job, keep particles and contaminants away from critical moving partrs.

for whom are you working ? is it a mail in sample place ?

I've been running it in everything. The Malibu and Escort I had got oil every 3 months which worked out to about 12,000 miles and a filter about half way through. The Malibu made it to 400k without burning oil just dripping about half a quart every oil change.

I've been running synthetic in the Mazda because it calls for it. It uses 0w20, and I've been using Mobil 1 or Castrol Edge, when I can find it. I change it every 7500 miles, and it hasn't burned a drop in 105k miles. In fact, the oil at 7500 doesn't even look that bad!

On my wife's Mazda, it takes 5W20, and I ran dino oil changed every 5K up until around 100k when I switched her to synthetic. I stretch it until 7500 now. Again, doesn't burn or leak a drop, and it loves it.

My Dakota does not get synthetic for it's yearly oil change, because it leaks it out anyway.

iadr wrote: A little OT: I've had bad syncro action by putting full synth 75w90 in a manual gearbox. (and automatics allegedly even worse problems)

Manual trannies are a weird case with fluids. It seems like every trans has some fluids it likes and some that it doesn't, even if they should be equivalent.

I was amazed that my 9-3 takes more oil than my friends V8 Dodge. 6 liters vs 5 1/2 quart.

Bobzilla wrote: But, if you're truly going to stretch out your OCI's, invest in OA to find that sweet spot for your needs. There's just too many variables for a blanket "this will work for everyone".

How much does oil analysis cost? I understand the value of the information it gives you, but if sending away for analysis costs $25 and it's $30 for a jug of T6 and a filter at Wal*Mart, I'm just going to change the oil instead.

Duke wrote:

Bobzilla wrote: But, if you're truly going to stretch out your OCI's, invest in OA to find that sweet spot for your needs. There's just too many variables for a blanket "this will work for everyone".

How much does oil analysis cost? I understand the value of the information it gives you, but if sending away for analysis costs $25 and it's $30 for a jug of T6 and a filter at Wal*Mart, I'm just going to change the oil instead.

Figure $30 - $40 for an analysis with TBN check. But it's not something you have to do for every oil change. I'd just do one after an OCI that's pretty representative of your average use of the vehicle and base my future changes on the results (slightly conservatively). If it indicates you can stretch another 2000 miles easily between changes, it'll pay for itself after a few cycles. Analysis per change is only worthwhile for vehicles that hold a ton of oil (expensive changes) and that see highly variable operating conditions, IMO.

Fear not, Rob.

If it helps, I switched from conventional to synthetic in the `92 Custom Cruiser. At 196k. The 350 hasn't leaked a drop.

Duke wrote: I've never witnessed the alleged "synthetic oil makes cars leak" syndrome in any of my cars, which range in age from 2012 and 45,000 miles to 1996 and 145,000 miles. I run it in everything.

It happened to my (EA82 engined) Subaru. 170k or so and never leaked and the oil would still be at the full mark after 3000mi. One of the things I liked about the car was that the drivetrain was totally leak free, a distinct difference from the old Ford that it replaced. I decided to switch to Mobil 1 to see if cold oil pressure improved (it did)... and after 2k miles, the oil pressure light came on because the crankcase was dry. The underside of the car... well it had most of a Subaru's worth of oil on it.

Of course, going back to non-synthetic did not stop it from leaking like a sieve, it merely got less expensive to drive.

Sometimes it happens, sometimes it doesn't. My Volvo lived a life of non-synthetic and long OCIs. Just great for a small all-aluminum turbo engine in a heavy car. I've been atoning for the previous owners' sins and it lives on ACEA synthetic (currently on Agip) changed at 1-2k intervals or so. Although last month I did finally get time to drop the oil pan and clean it out, lots of crust in there, so hopefully I won't need to change it so often and I can go to a normal 3k service interval. I switched to synthetic 18k ago and it's still leak free - it's at ~223k now.

Duke wrote:

Bobzilla wrote: But, if you're truly going to stretch out your OCI's, invest in OA to find that sweet spot for your needs. There's just too many variables for a blanket "this will work for everyone".

How much does oil analysis cost? I understand the value of the information it gives you, but if sending away for analysis costs $25 and it's $30 for a jug of T6 and a filter at Wal*Mart, I'm just going to change the oil instead.

http://www.polarislabs.biz/lubricants.aspx

Basically the advanced oil kit is ~$19 per kit and includes the mailer to send it back. Our private labels do sell them individually, but they typically cost a little more. I used my freebies on trans fluid for the Forte as well to get an idea if that 30k mile interval was too short or not..... its not.

rslifkin wrote:

Duke wrote:

Bobzilla wrote: But, if you're truly going to stretch out your OCI's, invest in OA to find that sweet spot for your needs. There's just too many variables for a blanket "this will work for everyone".

How much does oil analysis cost? I understand the value of the information it gives you, but if sending away for analysis costs $25 and it's $30 for a jug of T6 and a filter at Wal*Mart, I'm just going to change the oil instead.

Figure $30 - $40 for an analysis with TBN check. But it's not something you have to do for every oil change. I'd just do one after an OCI that's pretty representative of your average use of the vehicle and base my future changes on the results (slightly conservatively). If it indicates you can stretch another 2000 miles easily between changes, it'll pay for itself after a few cycles. Analysis per change is only worthwhile for vehicles that hold a ton of oil (expensive changes) and that see highly variable operating conditions, IMO.

This. But also keep in mind that single samples don't give you any trending data for failure items etc so doingthem more than once or twice is always a good idea.

Bobzilla wrote:

Duke wrote:

Bobzilla wrote: But, if you're truly going to stretch out your OCI's, invest in OA to find that sweet spot for your needs. There's just too many variables for a blanket "this will work for everyone".

How much does oil analysis cost? I understand the value of the information it gives you, but if sending away for analysis costs $25 and it's $30 for a jug of T6 and a filter at Wal*Mart, I'm just going to change the oil instead.

http://www.polarislabs.biz/lubricants.aspx Basically the advanced oil kit is ~$19 per kit and includes the mailer to send it back. Our private labels do sell them individually, but they typically cost a little more. I used my freebies on trans fluid for the Forte as well to get an idea if that 30k mile interval was too short or not..... its not.

Looks like you have to buy 10 at a time, or am i blind and don't see it somewhere?

NAPA/WIX does cheap oil analysis, $14.99+shipping it in, results emailed to you, does TBN, I think it doesn't have dissolved solids though (only important with a diesel). NAPA p/n FIL 4077

java230 wrote:

Bobzilla wrote:

Duke wrote:

Bobzilla wrote: But, if you're truly going to stretch out your OCI's, invest in OA to find that sweet spot for your needs. There's just too many variables for a blanket "this will work for everyone".

How much does oil analysis cost? I understand the value of the information it gives you, but if sending away for analysis costs $25 and it's $30 for a jug of T6 and a filter at Wal*Mart, I'm just going to change the oil instead.

http://www.polarislabs.biz/lubricants.aspx Basically the advanced oil kit is ~$19 per kit and includes the mailer to send it back. Our private labels do sell them individually, but they typically cost a little more. I used my freebies on trans fluid for the Forte as well to get an idea if that 30k mile interval was too short or not..... its not.

Looks like you have to buy 10 at a time, or am i blind and don't see it somewhere?

We only sell in 10-packs because 90% of our volume is large fleets, industrial etc. Amsoil has their program that sells them individually along with some other private labels we have.

Black stone labs will send you a single test tube, you only have to pay once you ship it in and I believe it's $20 or $25.

I should run my RX-7 out to 2,000 miles on an oil change and then send in an oil sample just to see what they say.

After 1k miles, the oil is 1 quart overfull from fuel dilution. That's why I never use synthetic in it, ever. The oil normally gets changed every 1k because of that, so long life isn't needed and if the oil temp gets over 150-160 degrees then the engine performance suffers, and if the oil gets over 200 degrees then engine LIFE suffers, so any heat resistance is completely moot.

"Wow Mr. Knurled, did you drain your fuel tank instead of your crankcase?" Maybe I should do it after using fuel scent. "Oil was free of metals, but was 30% gasoline and had a strong nose of vanilla"

Duke wrote: I've never witnessed the alleged "synthetic oil makes cars leak" syndrome in any of my cars, which range in age from 2012 and 45,000 miles to 1996 and 145,000 miles. I run it in everything.

I think that issue was primarily back when gaskets were natural fibers like paper and cork. They would age and crack, but the cracks filled with gunk. The higher solvency of synthetic oil cleaned out the cracks and you could get leaks.

I have switched cars back and forth between synth and regular without issue.

But I have a feeling if I put synthetic in the LeMans, it would leak so fast I would have to take a case of oil with me.

but to the question at hand from the OP, doesn't matter. blend it, change it, swap it, whatever. No preparation needed to swap oils either way. They are both slippery stuff and will both do the job well.