Synthetic Oil in high milage cars?

[halfasspunk]

I have been told that using synthetic oil in high milage cars can be bad, that it can actualy eat at gaskets or something like that, is this true, or is this just bs ?

 

[Machspeed]

Well i dunno about other cars, but shos should never have synthetic. Anyone got those pix of engines run on synthetic? Besides synthetic leaks really fast outta most shos anyway.

 

[halfasspunk]

So what is a good oil to use then? Also, I see people using 10w30 is that better for the motor than the 5w30 or does it matter?

 

[SHOZ123]

If your car isn't burning/leaking oil now it would be perfectly fine. In fact it would clean the motor up. If it is burning/leaking it may get expensive.

 

[shojuan]

Horsepucky

I've got 160,000 miles in mine. It had crap conventional oil for most of its miles. I put Redline 10W/30 synthetic in at about 148,000 miles. Nothing bad happened. I run the crap out of my engine too. Anybody in baysho will tell you. Lol, they think I run the crap out of my engine based on what they've seen. That was when I was being NICE to my car, lol! laughing

All the BS about not using synthetic oils in the SHO is BS. If you want to believe that crap but don't want to avoid synthetic oil then just avoid Mobil 1. Everybody who bitches about the synthetics really means Mobil 1 oil. Not that there's anything wrong with Mobil 1. It's just not the best. And I'll beat anybody over the head with a pole who extrapolates their anecdotal experience with Mobil 1 oil to other synthetics.

The good conventional oils that are out there are good oils though. I won't give anybody a hard time about using them. And the money you save can buy you a new(er) engine later anyways. I wouldn't use conventional in a track car though. Even if synthetic just cuts the wear in half on a track car it's worth it IMHO. And believe me, you *will* get accelerated wear in a track car. It's just how you decide to manage that inevitable wear.

Dave, I have no oil leaks with my 89 and the redline. I do use about a quart every 1000 miles or so (will hopefully go down after auto-rx treatment and a 2000 mile followup rest period with conventional GTX to let the cleaned seals relax against the cleaned metal). I do more than just wind my engine out to redline a couple times each day I drive it though. Gonna use some oil in an old engine driving it like that.

Oh, halfasspunk, to answer your question:

Conventional oil: Castrol GTX is a good one. Supposedly the Motorcraft 10W/30 you can get at walmart for $1.29 a quart is a good one too. Yes, in summertime in your climate use 10W/30. Much better weight than 5W/30 when using a conventional oil in above freezing weather. You want to minimize the point spread in muliweight conventional oils. There are other good conventional oils out there but I don't think I've ever heard a SHOwner bad mouthing Castrol GTX.

Synthetics: I like Redline. It's damn expensive though. I don't think much of the consumer grade synthetics that you can get at places like walmart (castrol syntec, pennzoil synthetic, valvoline synthetic, mobil 1, etc.) but what do I know? It's not like I've tested them all out or anything and even if I did it would take a proper (read: impractical) controlled scientific study to prove which ones are good and which are junk.

The new Mobil 1 0W oils are supposed to be very good actually. Even though they go against the rule of thumb I have about minimizing the point spread in a multiweight (most important for a conventional oil however) the 0W oils are supposedly better than the standard American 5/30, 10W/30, and 15W/50 Mobil 1s. I say American because the 0W oils were originally designed for the European market and they're factory fill oils for Porsche, BMW (I think BMW warranty for the M3 *requires* useage of a Mobil 1 0W oil. BMW repackages the oil and sells it as their own BMW oil btw.)

I might try out one of those Mobil 1 0W oils, probably the 0W/30 in my mom's Lexus ES300 next time I change her oil. She never changes the oil more than once a year in that car. She aspires too, lol! But unless I make a trip out there on Mother's day or something to do it, it just doesn't get done. Luckily she doesn't put many miles on the car. But shoot, regardless of mileage, you want to change oil at least once every 6 months if conventional and at least once a year if synthetic.

OK, I've written a book again and I only had a few things to say. I hope you're a fast reader, lol!

 

[shojuan]

SHOZ123:
If your car isn't burning/leaking oil now it would be perfectly fine. In fact it would clean the motor up. If it is burning/leaking it may get expensive.

Lol Paul! You beat me to it while I was writing my book. I didn't mean Horsepucky to you I was referring to the anti-synthetic sentiments.

Oh for synthetics I forgot to mention Amsoil oils as good ones. Though I am not at all familiar with the Amsoil line (which is extensive!) and I don't think I ever will be. I've got my west coast style Redline oil here hehe.

 

[sdpatt]

Case in Point #1 - Castrol GTX 10W-30 has allowed my engine to live a healthy, happy life for 276,900 miles now without cam lobe wear.

Case in Point #2 - I have performed valve gap adjustments on SHO engines with as few as 60,000 miles that have exclusively or primarily used Mobil 1 oil thorughout their lives and found significant cam lobe wear.

Case in Point #3 - On at least three SHO engines that were using Mobil 1 oil, the engine exhibited ugly, metallic noises during and shortly after starts following long downtimes.

 

[OSHSHO]

Learn all you ever wanted to know and more about oil, filters, additives, etc...search on "Bobistheoilguy"

 

[twr]

I used Mobile 1 10w-30 exclusively in my SHO for 35k miles. When I pulled the intake covers off I saw no appreciable wear on the camshafts or shims, but they were pretty dry (no oil) Since I knew I was going to be pulling the motor apart soon for the 3.2L upgrade I decided to throw in Castrol GTX 10w-30 for the next 3K miles, just a little experiment. When I pulled the valve covers off again, I could not believe that the camshafts were still coated with oil. I'm not talking a little oil, I mean dripping with oil. I can see where some of the cars Scott has see have had cam wear and noise on start up, dry camshafts are not a good thing. It does take a few seconds for the oil to reach the shafts. As Scott can attest from previous oil discussions, I was always stating that I would always use Mobile 1. No more, I will be using Castrol GTX in my 3.2L motor.

<small>[ June 19, 2003, 09:59 AM: Message edited by: twrsho ]</small>

 

[SHOZ123]

Mobil one 5w30 use to have a very low viscosity rating on the 30 weight end. It really was closer to a 25w oil. Personally I use Amsoil.

 

[Markus]

sdpatt:
Case in Point #1 - Castrol GTX 10W-30 has allowed my engine to live a healthy, happy life for 276,900 miles now without cam lobe wear.

Case in Point #2 - I have performed valve gap adjustments on SHO engines with as few as 60,000 miles that have exclusively or primarily used Mobil 1 oil thorughout their lives and found significant cam lobe wear.

Case in Point #3 - On at least three SHO engines that were using Mobil 1 oil, the engine exhibited ugly, metallic noises during and shortly after starts following long downtimes.

Scott, my responses:

1) I have no doubt that Castrol GTX is a good oil. You have clearly shown it to work well. I have found Mobil 1 to be a good oil. The links to my pics below confirm this. Neither myself nor Josh T. (when he dropped by my house to deliver some shims) could find any sign of cam lobe wear. These pics were taken at 169,000 km. I have been using Mobil 1 5W30 since the odometer read 20,000km (12,000 miles). I change the oil every 5000km (3000 miles) and use only the Ford FL400/FL400S filters. I think I can safely state that engines using GTX or Mobil 1 oil will exhibit minimal engine wear if the engines were treated properly (see my response below). I know your engine has never been neglected and neither has mine. In addition, when using Mobil 1 (and a few other synthetics I have tried) my engine idles MUCH smoother and runs MUCH quieter than with a dino oil. I have not, however, actually tried Castrol GTX. Perhaps I would find that it offers the same benefits as synthetics. I simply don't know!

2) Simply stating that you have seen low mileage Mobil 1 engines with cam wear is meaningless. How were these engines treated? How often was the oil changed? What oil filters were used? Were some of the scheduled oil changes simply forgotten? Were the engines driven extremely ******* a daily basis? In what climates were the cars used? How well did the engines warm up (very short trips in cold winter weather will not allow then engine to warm up, and we all know this is not good)? Had all required services been performed on the engines? Did the engines have an overheating/underheating problem? Had the engines been allowed to warm up before they were driven hard? Case in point: I have a friend who has only used Castrol GTX and changed his oil every 10,000 miles. His engine now has 100,000 miles on it and it is now burning oil at the rate of 1 litre every 500km (300 miles). I could simply state that his engine wear resulted from the use of Castrol GTX, but I would probably be wrong. Without a full analysis my statement is meaningless.

3) I have never experienced this noise. Never!

Based on my experience I say Mobil 1 is a good oil.

lobes

more lobes

head

another head

 

[sdpatt]

Markus:
2) Simply stating that you have seen low mileage Mobil 1 engines with cam wear is meaningless. How were these engines treated? How often was the oil changed? What oil filters were used? Were some of the scheduled oil changes simply forgotten? Were the engines driven extremely ******* a daily basis? In what climates were the cars used? How well did the engines warm up (very short trips in cold winter weather will not allow then engine to warm up, and we all know this is not good)? Had all required services been performed on the engines? Did the engines have an overheating/underheating problem? Had the engines been allowed to warm up before they were driven hard?

The one 60,000 mile engine was owned by a dedicated owner who regularly replaced the oil and filter at 3,000 mile intervals. He paid the extra cash for Mobil 1 because he wanted to use the "best" oil. He brought the car to me because he wanted to take the best care of his prized possession. He drove the car very gently by my standards. He babied the engine. He was very disappointed in my findings, but changed to Castrol GTX and said he found the engine to be noticeably quieter at startup.

The points stated previously were not my opinion. The information in this reply is not my opinion. I did not make any claims. I just described my observations as a professional engineer.

 

[shojuan]

sdpatt:
Case in Point #1 - Castrol GTX 10W-30 has allowed my engine to live a healthy, happy life for 276,900 miles now without cam lobe wear.[qb]

Scott, start open tracking your car and get back to me on the wear issue.

[qb]
Case in Point #2 - I have performed valve gap adjustments on SHO engines with as few as 60,000 miles that have exclusively or primarily used Mobil 1 oil thorughout their lives and found significant cam lobe wear.

</strong>Scott, that's not science.

Case in Point #3 - On at least three SHO engines that were using Mobil 1 oil, the engine exhibited ugly, metallic noises during and shortly after starts following long downtimes.

Scott, that's not science.

Scott, you are too well respected here to not question your anecdotals that really should have some scientific backing when coming from somebody such as yourself. People will believe you just because you're Scott (and kudos to you. You've earned that reputation). Do you see where I'm going with this? It's sort of an "abuse of power" thing. Some poor sap is going to take his car to the track and run all day on Castrol when he could have been using something with more protection.

 

[sdpatt]

I didn't say they were scientific. I said they were merely observations. You choose to use synthetic oil that isn't Mobil 1 and your engine is still running. I choose Castrol GTX and my engine is still running. Let's leave it at that.

 

[yamahaSHO]

FOR SHO:
Well i dunno about other cars, but shos should never have synthetic.

Yeah, 'cause you know the SHO has "special" metal from Crypton jpshakeh

 

[halfasspunk]

Okay, but I heard that after a car uses non synthetic oil for a long time, and then you switch to synthetic it can clean the seals and gaskets away, is this true?

 

[shojuan]

halfasspunk:
Okay, but I heard that after a car uses non synthetic oil for a long time, and then you switch to synthetic it can clean the seals and gaskets away, is this true?

no.

 

[rendyx]

I run Mobil-1 10w-30 in my 91, and I can say it works great. It does run out a little quicker, yes, but seems to lubricate very well. I am just careful to give it a good time to build oil pressure every morning.

 

[Bluto]

I've never used it in my SHO.
I have used it in two other cars of mine, and both times oil would leak or seap a lot more when using synthetic.

There is no doubt it doesn't break down as much as org.

I hate oil leaks, and I change my oil every 3grand with organic. No leaks. Even with synthetic I changed my oil frequently(4,000).

This is just my experience.

 

[yamahaSHO]

Bluto:

There is no doubt it doesn't break down as much as org.

Actually, synthetic doesn't break down... it just gets dirty.