Synthetic vs. Dino. By a Mechanic.

[TomSeller]

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

I always mark mine for a 3000 mile change so that I get around to changing it at about 5000 miles.

 

[TomSeller]

Keep in mind thatwith synthetic oil all the molecules are exactly the same size as with dino they are all different sizes.So if you have a leak with dino oil you will have one **** of a leak with synthetic

Same goes for engines that are built to consume some oil. I have a Cadillac Northstar engine that drinks synthetic oil to the tune of a quart about every 600 miles. But on Dino it gets 2500 miles before needing a quart.

 

[daugen]

I remember a synthetic oil report,possibly in consumer reports,that showed Valvoline Full synthetic to be BARELY better than non-synthetic

yikes....well, maybe that's why I got such a good deal on it. I usually want synthetic for cold weather starting, so if it does that better, and is no worse than dino oil,
which I think we all will agree that the good stuff today really is good..., maybe I got my money's worth for four bucks a quart.
Makes we want to reconsider Tractor Supply's own brand, wonder who makes that?

 

[daugen]

Same goes for engines that are built to consume some oil. I have a Cadillac Northstar engine that drinks synthetic oil to the tune of a quart about every 600 miles. But on Dino it gets 2500 miles before needing a quart.

I've had two cars with that engine, a Cadillac and a Buick Lucerne. The engines were marvelous, made great noises, not a huge amount of power (not a big engine for sure) and was supposed to be the absolute state of the art
when it came out. They even supercharged it for several models. And the thing leaks like a sieve? What was the bad design? Using four times the amount of oil is quite a difference; most of my recent cars haven't used more than half a quart of oil between changes.

 

[clemsonfor]

MOST do not run synthetic for the 'break-in' interval however, because synthetic does NOT help the internal engine parts seat in properly, whereas the dino will allow the parts to 'break-in' properly. After that initial time synthetic is fine.
YMMV

I think this is a often paroted miss information line. I see the point and know some engine manufacturers do say this but if this is the case why do certain cars (germans) some catilacs, corvete other Gms, run SYN from the factory?

 

[dodge man]

The Northstar is a good engine, and yes, it was state of the art when it came out. I don't know where they leak from, normal gaskets I think. Just because its considered a "premium" engine doesn't mean its more immune to leaks than others. Just from what I've read on the internet, the only weak spot is if they overheat. Like most engines, water pumps will fail, and if you run a Northstar hot, they will pull the head bolts out of the aluminum block. This can be repaired with a helicoil like setup, but its expensive.

My sons Aurora has a Northstar, and other than the fact it leaks oil, maybe a quart every 800 miles, its been a good engine and a good car. The only thing the engine needed was a water pump.

 

[Diamondpilot]

The Northstar is a good engine, and yes, it was state of the art when it came out. I don't know where they leak from, normal gaskets I think. Just because its considered a "premium" engine doesn't mean its more immune to leaks than others. Just from what I've read on the internet, the only weak spot is if they overheat. Like most engines, water pumps will fail, and if you run a Northstar hot, they will pull the head bolts out of the aluminum block. This can be repaired with a helicoil like setup, but its expensive.

My sons Aurora has a Northstar, and other than the fact it leaks oil, maybe a quart every 800 miles, its been a good engine and a good car. The only thing the engine needed was a water pump.

My grandfather owned a Dodge/Chrysler dealership for about 40 years. He sold to his brother on a Friday and on the following Monday me and him went and bought a new Caddy with a Northstar, a Model A, and a Ford F250 cash. This was in about 1988 or 1990, can't remember. Took a while to negotiate the Model A. He was just cheap. He always wanted all three but could not have them other brands and sell Dodges and Chrysler with a strait face.

Anyways, it drove him nuts for the year he owned it that the Northstar used oil. He tried everything but the only thing that slowed down consumption was Kendall Motor Oil.

He traded that caddy for a Lincoln and drove multiple Lincoln's till he could no longer get a license.

Chris

 

[don45640]

Hey,my òl Granpappy Wright was smart too! He had a Plymouth way back when...but he lived up on a steep mountain road.He got tired of barely makin'it,so he put a Ford V-8 in the Plymouth and solved the problem.LOL! ^)

My grandfather owned a Dodge/Chrysler dealership for about 40 years. He sold to his brother on a Friday and on the following Monday me and him went and bought a new Caddy with a Northstar, a Model A, and a Ford F250 cash. This was in about 1988 or 1990, can't remember. Took a while to negotiate the Model A. He was just cheap. He always wanted all three but could not have them other brands and sell Dodges and Chrysler with a strait face.

Anyways, it drove him nuts for the year he owned it that the Northstar used oil. He tried everything but the only thing that slowed down consumption was Kendall Motor Oil.

He traded that caddy for a Lincoln and drove multiple Lincoln's till he could no longer get a license.

Chris

 

[TomSeller]

Actually my Northstar does not leak oil at all, it consumes it. Those engines according to an old internet posting I saw once were made with a more coarse bore to carry oil on the cylinder walls more like a racing engine. Combined with lighter fitting rings resulted in a little oil usage. Add little white haired ladies driving their Cadillacs to the grocery store and back day after day didn't help many of them. I follow something I saw from one of the original Cadillac engineers who said to do about 10 cycles of WOT in 2nd gear to redline, including full deceleration. The deceleration was supposed to lift the rings out of the seats to reduce the carry over oil. It seemed to work for me, cutting oil consumption considerably. The trouble is more finding an empty highway where you can do this often enough. I don't consider this a fault at all with the engine. They run good.

 

[lostcause]

where i live, i don't think there is really any benefit from running synthetic on the thought that it will make your engine last longer. as others have noted, engines and lubricants are so much better than they used to be, and they will run for as long as you want (barring freak exceptions) as long as they are maintained reasonably well. around here you will almost always lose a vehicle to corrosion before you do an engine failure. if rust isn't the cause of death, then the transmission will likely be it. when the engine is lost, it is usually due to a broken timing belt on an interference engine.

even with that, i'm now running synthetic oil in my 3 main vehicles:

my car came from the factory with synthetic (mobil 1) and now gets a yearly (~6k miles) change with amsoil (it was the easiest to find on the shelf that met the gm-ll-a-025 spec).

i have a ton dump with a duramax that i always ran conventinoal rotella 15-40 in until one cold morning when i was headed out to plow. it was really cold and i wasn't sure it would start, though it did. what it didn't do was pump the oil. it was like hitting the jackpot on a slot machine when you see all the flashing lights and bells going off when you have zero oil pressure. after losing a couple hours due to plugging the block heater in i started going with synthetic rotella 5-40 i think? i haven't had a problem in the cold since.

my other truck was the last to switch to synthetic on. i figured i'd try it, since it's a cheap change at 6 quarts. what i noticed was that it was more consistent in the cold. when standing outside of the vehicles in the cold you do't get any indication of a labored engine with the synthetic. on the cold days it just didn't sound as smooth with conventional oil.

i'm not sold on the extreme long oil change intervals yet. that may just be because i grew up on the 3k change pattern. my reasoning is that the oil isn't just a lubricant, but it's a filter too. no matter how good the filter is, the oil is bound to pick up some contaminants, not to mention any moisture or fuel that gets into the system. i do my changes at 5-6k now, which you can get by with on conventional oils.