Conventional vs Synthetic Oil Debate

[98 Nitro]

Yeah I am in agreement with you for the most part, I do believe synthetics have formulas and additives that will provide better wear protection and make it last longer between intervals, but i will probably just stick with my Valvoline High Mileage Synthetic Blend 5w30 with ZDDP additive in my 89 and 95 chevy. Always works great.

I use the Valvoline hi mileage 5w30 as well in my Tbi and Vortec trucks, and have no problems with 2 200K mileage truck engines. I do not use zddp additives, I think it is just needed for flat tappet cam break in.

 

[BNielsen]

I used to run Pennzoil in my 96 454, mainly because it was what the previous owners ran.
Made the switch to Amsoil and haven't looked back; I don't know if it was coming from the low quality oil or something else, but after my first two oil changes on Amsoil my engine ran quieter, less clattering and other obnoxious noises like that.
It even helped me with MPGs, only by like .5 a mile or something like that, but on a Big Block that's decent enough in my opinion.

 

[DerekTheGreat]

For a short time I was involved in the fuel/oil industry. I worked for Chevron.

At one of the district meetings I went to, I was at the same table as one of the chemists that formulated oil. Somebody asked him about all the over the counter additives that supposedly make oil better. His response was the over the counter stuff does more harm than good. He told us when mixing and proportioning the additive package for oil, changing one of the additives a little as 1/4% can mess up the whole additive package. It is a very fine balancing act to get all the additives to play nicely together. Throwing in whatever bottle of snake oil (as he called it) 99.99999% of the time will undo what you spent good money for in the first place.

Ken

Watch the video:

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I believe thats the one I watched. I read articles which stated similar things to what you have. Up until that PF video, I never added anything to my oil. I've put over 25k on my truck's engine with this stuff and no ill effects yet.

 

[LVJJJ]

to open up a bit of controversy. In the past I have read that the only two real synthetic oils are Amsoil and Mobil 1. All the other companies sued to have their super refined oils considered synthetic. They won. So, I only use Mobil 1

 

[1989GMCSIERRA]

I’ve been using Supertech oil for about 20 years now in my cars. Now that their synthetic brand is not much more than the regular I switched to that. In my diesel I use Traveller 15-40.

My gmc has 396.000 miles on the original engine. My diesels have 160,000 and 180,000. My wife’s suv has 196,000 miles.

the main thing is.......I change my filter and oil regularly. That’s it. That matters more than what oil you use. My last daily driver I used super tech. At about 140,000 the valve cover was seeping. I replaced the seal. The cam towers avd top of the head looked clean. No deposits no crud. The only thing was there to see was the light brown honey stain. The cams and lobes had no wear. The lobes all felt smooth all the way across. My other daily gets oil changes every 5,000 mikes but it gets driven at a constant 70 mph on a freeway both ways. I did a sample to Blackstone and they said I could extend the oil changes. I’m currently doing my first 7500 mile change avd I’ll send a sample see what they say.

 

[Trenton]

If you convert to synthetic on a high mileage vehicle, expect oil leaks and to start burning a little oil. I have discovered that issue on 3 different vehicles. That's the better detergent additives doing their magic and scrubbing through carbon build up keeping the gaskets and seals from leaking.

That being said, synthetic is superior oil, through and through, especially the more expensive stuff. I run Amsoil in my truck. Ive seen tests and experienced the wonders. I run it in my '97 K3500 5.7 in the engine, t-case, and differentials. Things generally do run smoother and my oil pressure even went up.

In general, though, a good oil is not effective without a good filter. I use the Wix XP filters, because I love Wix products, but any Wix, Mobil 1, Amsoil, ACDelco, Motorcraft, Mopar, etc oil filter will do just fine. Stay away from cheap filters (*cough* Fram) or the ones used at quick lube places. They get away with being cheap because the filter media is garbage and sometimes they don't have a drainback valve or pressure valve.

If you're adamant on your engine lasting as long as possible, use Amsoil and an Amsoil or WIX XP filter. If you just want your engine to be kept up, just get a decent oil and use a good filter at 3-5k intervals.

 

[Ehall8702]

Always ran a synthetic blend high mileage valvoline or conventional shell rotella, but heard yelling from both sides of the fence. Conventional is best or synthetic is best, this and that etc etc.

I'm just looking for longevity and best preservation of my engines.

So... what to use? Have 3 motors, 140k miles, 220k miles and 280k miles.

PS: I know it's dumb lol but it's gotta be settled.

Best answer is just put oil in it and CHANGE IT REGULARLY! I've run both with no real issues or benefits of each I could tell. Our trucks don't NEED synthetic oil, the ls motors on the other hand NEED synthetic cause the brainiacs at gm designed the afm system to shut oil pressure off to moving lifters???

 

[LC2NLS6]

I use K&N filters because I can put a 1 inch socket on them to remove them.

 

[L31MaxExpress]

If you convert to synthetic on a high mileage vehicle, expect oil leaks and to start burning a little oil. I have discovered that issue on 3 different vehicles. That's the better detergent additives doing their magic and scrubbing through carbon build up keeping the gaskets and seals from leaking.

That being said, synthetic is superior oil, through and through, especially the more expensive stuff. I run Amsoil in my truck. Ive seen tests and experienced the wonders. I run it in my '97 K3500 5.7 in the engine, t-case, and differentials. Things generally do run smoother and my oil pressure even went up.

In general, though, a good oil is not effective without a good filter. I use the Wix XP filters, because I love Wix products, but any Wix, Mobil 1, Amsoil, ACDelco, Motorcraft, Mopar, etc oil filter will do just fine. Stay away from cheap filters (*cough* Fram) or the ones used at quick lube places. They get away with being cheap because the filter media is garbage and sometimes they don't have a drainback valve or pressure valve.

If you're adamant on your engine lasting as long as possible, use Amsoil and an Amsoil or WIX XP filter. If you just want your engine to be kept up, just get a decent oil and use a good filter at 3-5k intervals.

Funny you say that. I have switched two different higher mileage engines to synthetic. After about 10-20K miles the oil consumption dropped in half and no external leaks for a long time after. I swapped my VQ35HR to synthetic at 130K. Was not until it had 200K on it that it started leaking a little at the valve cover gaskets. It is an 07 and the rubber valve cover gaskets had become as hard as plastic. Synthetic cleans the sludge out of the oil control rings with a little time allowing them to unstick and perform like they should. I have never pulled apart an engine run on conventional oil that did not have a nasty buildup on the bottom of the pistons and oil control rings but always see clean pistons and oil rings on synthetic. The 350 that came out of my Express van at 70K has pistons that look like new.

 

[DerekTheGreat]

If you convert to synthetic on a high mileage vehicle, expect oil leaks and to start burning a little oil. I have discovered that issue on 3 different vehicles. That's the better detergent additives doing their magic and scrubbing through carbon build up keeping the gaskets and seals from leaking...

Not true, least not in my experience. I convert every vehicle I purchase to full synthetic. Never noticed any additional leaks or oil consumption. That rumor is pure poppycock which unfortunately continues to spread. Although I suppose I could be persuaded to buy into the whole "dirty engine made clean by synthetic now leaks" type thing but I've never seen it. Until I do, my opinion probably wont change but I might smile and nod to those who try and tell me that sort of thing.

My '88 Town Car had zero leaks while run on dinosaur syrup and still has zero leaks after some 40k miles and five years on full synthetic. It doesn't use any oil until after 1,500 miles or so into the oil change. Similar deal with my '89 K1500. New used engine went in at ~224k miles and it had about 140k on it for whatever that is worth when it went in. Truck now has about 255k on it and has only seen Valvoline SynPower up until it's last oil change where it got Shell Rotella T6, 5W-40. It doesn't start to use oil until about 2500 or 3,000 miles into it's 5k interval. And at that point it's negligible. The old engine used about a quart every 300 miles and was down one cylinder. Rear main seal has started leaking but it was new at the time the engine was installed, as well as all the other gaskets.

My wife drives a '92 C1500. As far as I can tell, it's all original. 213k miles, we got it with 201 or 202k. I don't really give two squats about mileage on old vehicles but since the majority does, I use it to my advantage. On the test drive, it had a very minimal amount of blow by coming out the oil fil cap with the PCV valve removed, what I could see through the oil fill hole looked extremely clean and so was the throttle body. No leaks, just seepage surprisingly. Got it home, dumped out whatever was in it, put the Valvoline stuff in it along with WIX filter and for the past two 5k changes and it's oil consumption is exactly identical to my truck, minus the rear main seal leak. It'll get Rotella T6 as well come 215k.

My '89 Fireturd has used oil for as long as I can remember. My dad took the guy he bought it off of to court over it. It'll use about the same amount of oil per 300 miles as the old engine in my '89 K1500. That number didn't change when I started using synthetic. Dad sure as hell didn't use synthetic in it. Only thing he did was change it about every 3k.

Should be noted that MotorKote additive goes in with every oil change on all our cars as well.

to open up a bit of controversy. In the past I have read that the only two real synthetic oils are Amsoil and Mobil 1. All the other companies sued to have their super refined oils considered synthetic. They won. So, I only use Mobil 1

I’ve been using Supertech oil for about 20 years now in my cars. Now that their synthetic brand is not much more than the regular I switched to that. In my diesel I use Traveller 15-40.

My gmc has 396.000 miles on the original engine. My diesels have 160,000 and 180,000. My wife’s suv has 196,000 miles.

the main thing is.......I change my filter and oil regularly. That’s it. That matters more than what oil you use...

Project Farm has other videos where he does oil shootouts. I have not seen this lawsuit so it could also be poppycock but regardless, the way Valvoline performs as well as Rotella is up there based on his testing. How things perform during testing is what matters to me. I personally like that wear scar test he does as well as the heat resistance test and cold flow properties. So oils may all keep stuff clean, but what sells me is how well they protect against wear.