Synthetic vs. Dino. By a Mechanic.

[speedyspider2050]

I have read many threads with people asking the ? Which oil type to use. I have been turning wrenches for a living for 37yrs. So hear is my personal experience with both oils. I rebuild approximately 3 to 5 engines a year. The engines I rebuild that run strictly Dino oil have what we call coking(Varnish build up) all throughout the engine, Heads, block and crank. I have yet to rebuild an engine due to oil failure. But the engines I rebuild that have run synthetic oil are very clean and no coking(varnish buildup) in any of the components. I rebuild both gas and diesel engines so this applies to both. I personally have rebuilt my own engines and run only synthetic in them. My diesel suburban and Mitsu D2050FD both get Mobil 1 5w-40 full synthetic turbo diesel oil. My other two gas engines run Mobil 1 5w-30 full synthetic oil. I also use Lucas synthetic oil stabilizer in all my engines as well. So from a mechanics stand point synthetic oils do have the advantage of keeping your engine internals cleaner than conventional dino oils. Hope this helps a few people make the decision to run the oil they want. As for the cost difference here is the basic math. Just a few figures thrown out here. Basic oil change with dino oil $30.00 to $40.00. Change every 3000 miles. so for 6000 miles next oil change you spend another $30.00 to $40.00 . Ok synthetic oil change runs roughly $45.00 to $55.00 and you change it every 6000 to 7500 miles depending on the driving conditions. So do the math. Synthetic is less money and in my opinion better for the engine. I personally have my oil analyzed and determine from that when to change my oil. But i never run more than 7500 miles before a change. As for my tractor I change it every 125hrs. Just my thought and experience with the two different oils. Not saying that dino oil is bad. Just saying that synthetic keeps it cleaner longer and runs longer intervals before needing to be changed.

Preston Bowman: Certified Master Tech GM, Ford,Chrysler:cool2:

 

[timswi]

Agreed...I run Mobile1 in all of my stuff now and never had a problem...Used to use Castrol GTX dino and that never caused me any issues either...General mainentance was always maintained.

Tore down the 396 in my Chevelle once and it was spotless using the Castrol...Although the next rebuild will get synthetic going forward...Just seems like better stuff to me.

 

[Markcuda]

My wife ran her 2003 Neon to 375,000 miles with out a dino oil break down.

 

[texasjohn]

I like synthetic, Mobile 1. Have used it for years. In tractor too...the diesel rated oil.

 

[Locoweed]

I haven't changed oil at 3000 miles in many years, never had oil related engine problems.

 

[Markcuda]

The 3000 miles oil change intervals are a scam/scare tactic.

 

[JBourquin]

I change at 5000mi on everything I own. Full Synthetic in truck, car, bikes, sleds, mower...

 

[CurlyDave]

OK, now how about the Mobil 1 EP oil?

They claim 15,000 change intervals. As soon as any rig I own goes out of warranty, I switch to Mobil 1 EP and increase the oil change interval to 15,000 miles. Am I OK, or am I wearing something out?

BTW, the EP oil is $3-4 per gallon more than the regular Mobil 1 at Wally World, so the economics are impressive.

 

[TheGoose]

I don't run synthetic fuel so why bother with synthetic oil?

BTW oil for an avg. truck doesn't cost $30-40.

 

[nspec]

'09 gmc sierra 1500.....5.3 liter v-8.....mobil 1 5w-30 costs $30 for an oil change

 

[speedyspider2050]

Goose... The prices I quoted were for people that take their rigs in and get the oil changed. Not prices for do it your selfers. 80% of people take their auto's in to a shop for an oil change. But your statement of......

"I don't run synthetic fuel so why bother with synthetic oil? " tells me you are cheap and probably buy bargain oil for your rigs....

Like I said in the beginning of my post. "JUST MY OPINION ON OIL" I am not trying to bash any oil's on the market. Just saying what my preference is and what I have seen tearing engines down that run the 2 different types of oils. It is just my opinion as a mechanic. So people can buy what they want.

Curley Dave... I don't know about the Mobil 1 EP. If I were to run 15.000 miles between oil changes I would take oil samples at 5000 mile intervals and have it tested for molecular break down. Can't say one way or the other as to if it's capable of 15.000 mile intervals. Hope this clears up my post and helps you out Curley... Have a nice night all..... Preston

 

[dodge man]

I'm running Amsoil in most of my vehicles. I'm changing it once a year, which is anywhere from 6000 to 10,000 miles, depending on the vehicle. Amsoil says you can go 25,000 miles, but thats more than I'll ever run it. The way I look at it, even if it costs a little more, thats maybe one less time per vehicle I'm under the vehicle. We now have 5 vehicles I maintain so every little bit helps.

The exception is my sons 99 Aurora with a Northstar v8. It leaks and it leaked worse with Amsoil so I switched back to dino oil. It leaks less now.

 

[speedyspider2050]

Dodge man ... I feel for you with the Aurora... I worked on those for a few years. They leak like a siv. Used to replace at least 6 pan gaskets a month on those when they came out. Have you tried the Lucas engine stop leak? got a few to quit leaking with that product. And Amsoil is a great oil.

 

[Ken45101]

OP, thanks for the perspective.

Yes, I figure the economics favor synthetic since I run it at the 6000 mile change interval.

I haven't been able to bring myself around to using synthetic in the truck however, which uses 15 quarts IDK about a longer interchange interval there since it only gets changed about once a year with conventional Rotella.

 

[Gary Fowler]

When I bought my Chevy truck, the salesman told me to read the manual and follow it for oil changes. It has on board computer like most Chevy products since 2003 for sure and the computer is calibrated for DINO oil use. It usually takes about 7000-7500 miles to trip the computer to 0 miles before oil change. Since I rarely go that many miles in a year between our two vehicles, it is basically a yearly change which keeps in mind with the GM engineers. I started using synthetic a couple years ago and feel confident that I could extend the time line and mileage if I wanted without any harm to my engines. I changed my oil in 2011 in July and then made a trip to Riverside Wyoming and back then it got used occasionally for the rest of the year, then I was mostly away for first 6 months of 2012 and my truck got little use. I didn't change the oil till Oct. 2012 (15 months) and it was still as clear as the old Exxon dino oil when it is in the bottle. I did exceed the time but not nearly the mileage per the computer. Since it sat in a closed shop all the time, I don't think it is subject to condensation like outside stored vehicles.
I think the old 3000 mile oil change was just a gimmick for shops to increase their work and thus profits. Ford cars as early as 1965 (first one I remember) had 6000 miles recommended oil changes as did my 1970 Torino and my 1974 Mercury Grand Marquis. NOW they are 7500 and with lots better oils today than 40 years ago and folks are still going to JiffyLube and other places including car dealer shops every 3000 miles and throwing away perfectly good oil.

 

[Ed of all trades]

Just don't run a motor up to high miles on dino and then swap to synthetic, I know some motors come apart when that is done.

 

[Ken45101]

In the old days, engines didn't last nearly as long as they do today. Better engines and better oils. Note that oils that met specs 30 years ago do not meet modern specs.

I do detest the oil change locations that slap on the 3000 mile sticker no matter what the car manufacture recommends! You are right, it's a money making rip off in most cases.

Note, on some cars, manufacturer's recommendation is for synthetic only. Corvettes come to mind but I know there are others.

 

[teampryor]

mobil 1 5w 20 ep oil change by me every 10k using premium fram filter rated for 10k. in my gas powered 2011 f250.

 

[Buppies]

A while back had a 1983 BMW 5 series my dad had. The computer on the car would tell you when to change the oil and it was not recommended by BMW at the time to run synthetic . Oil change light would go off between 2800 and 3500 miles. The car had about 100000 miles on it when corp. BMW said synthetic was ok and switched to amsoil. Computer on car would now go off between 6500 and 8200 miles. When car got up to about it started using water dealer tore into motor and found part that was defective which BMW warranted. Pictures were taken and sent to Germany to show the lack of wear and how clean the internal parts were. Have been using synthetic for years and will continue to do so. 2001 dodge 2500 had two oil filters with amsoil changed one filter at 10000 miles oil and both filters and oil at 50000 mile intervals. Oil was analyzed at each 10000 mile interval. Sold truck with 210000 miles and it is still going strong with over 300000 on it

 

[dodge man]

Dodge man ... I feel for you with the Aurora... I worked on those for a few years. They leak like a siv. Used to replace at least 6 pan gaskets a month on those when they came out. Have you tried the Lucas engine stop leak? got a few to quit leaking with that product. And Amsoil is a great oil.

The Aurora only leaks maybe 2 to 3 quarts between oil changes, so I probably won't mess with it unless it gets a lot worse. I haven't really figured out where is leaking at for sure, you can smell the oil on the exhaust after its been run. It could just be valve cover gaskets. I've tightned up everything I can get a wrench on but it didn't help much. Its my sons first car, he is eighteen now, and so far the only thing I've done to it beyond brakes is a water pump.