Oils: To Synth or not to Synth?

95pearlbird

Registered User
I recently purchased a '95 SC w/ 99K on it. The previous owner ran nothing but Castrol Full Synth 5~30 in it. I thought that I would start a thread on this simple question with many answers. First, I was interested in what other SC Owners are running in their cars. Full Synthetic, Blended or Petroleum(Standard) Oil? Is there one brand that most prefer? In high heat/ stress conditions, I've seen Castrol turn to a very watery viscosity. In similar conditions I've seen Valvoline Racing hold up great. Also had good luck with Kendall, but these experiences were always with 20-50 viscosity. Do others regularly change the viscosity they use between winter/summer? Someone from New York may have totally different preferences from someone in Phoenix. I live in Palm Springs, and have seen it hit 122 here!!
Isn't 5~30 going to thin out awful bad under that kind of heat?
Is Full Synthetic really worth the extra money?
Please list the brand and viscosity you like to use, and whether you use Full Synthetic, Synth Blend, or Regular ole Oil. Whats your preference? Also, please list if you are a daily driver, or a strip only SC owner.
Since we are all performance enthusiasts, enjoying high output engines, (that reads as ~HORSEPOWER, Baby!) I thought it might be an interesting subject: To discover if there is a common thread of experience that"most" use.....
Thanks for joining the Feedback!
Got to fly Fast to beat these 'Birds!
 
SC motors tend to dirty the oil very quickly. You're better off to do frequent changes with top quality 10W30 mineral-based oil. In your climate, 10W40 is probably advisable in the summer.

cheers
Ed N.
 
I change the oil every 1500 miles or major breakdown (which ever comes first), so it doesn't pay for me to run synthetic.

David
 
I fully believe that the oil recommendations for SC's by Ford was a mistake. I've had many SC engines apart and every single one of them had bad rod bearings. In fact, by 100K miles I'm almost certain that you have copper linings showing.

What does that mean? 1) you have no "cushion" in the bearings anymore. Any contact of the crank to the bearing surface is going to cause wear. 2) you have no imbedibility of the lining. If dirt gets in, its going to eat the heck out of the journals. 3) oil pressure is going to be reduced.

With these factors, I personally run and recommend a heavier oil. In summer time I run 50wt oil and in the winter - well - I don't run it in the winter. My personal choice is Mobil 1 15/50 and I run it until it gets dirty and/or a quart low. Testing has shown that the oil has not lost any oiling properties in even 15K miles nevermind 3K. I recommend filter changes at 3K mile intervals (or sooner!). Contamination wise, I don't necessarily agree with Ed completely. My oil does not get dirty quickly, and in fact I usually change my oil once a year in fall before I park the car. If you are experiencing high levels of contamination, then something is not right, and yes, the oil should be changed more often in that case. With 190K miles on my car it uses a quart about every 5K miles.

My car sees all kinds of use. My wife drives the kids around in it, we go on long trips (usually 3-5K miles a year in trips alone), and I race it whenever I get the chance. It sees in excess of 18psi boost and 6000rpm regularly and makes over 400rwhp so it's no slouch.

Hope that helps!
 
Valvoline Synthetic Maxlife 10w30 year round.
I had worked for Valvoline Instant Oil Change for about 4 year and have seen the stuff do what it promotes (slow leaks and oil burning) but alas i did not have such luck. i was hoping to not have to do the oil pan gasket... but thats on the list for this summer. since that is my only leak, ill proabbly go to full syn. after the gasket change.

ps. the maxlife did work on my wifes Taurus
 
I've had 3 SC's and still own 2. I've driven over 400,000m altogether and never had an engine failure. Once the new engine was 'broken-in' (say 1,500-3,000m) I've switched over to Mobil 1 - 5w30 in the winter months & 10w30 the rest of the year. I believe the synthetic is worth it in supercharged engines (especially a factory engine v. a race built one) because they run so hot and would likely cause excessive vapor/sludge build-up with conventional oils. I change the oil & filter every 3,000m because it does get dirty (likely blow-by), yet I never add any oil between changes - EVER. My '90-5 speed I drove for 100,000m and then a friend bought it and he went all the way to 246,000m before the HG's blew. My '93-5 speed my Son has at the moment and that has over 210,000m & my current '94-auto is now over 120,000m. I'm interested in what the engine builder said about light viscosity, so maybe a 10w50 synthetic would be better. However, stretching the viscosity rating of convention oils beyond a 25w difference, like 10w40(30w difference) has driven auto manufactureres to deny warranty claims, because the oil companies have to put in so much polymer additive it reduces the quantity of base oil. Therefore using a conventional 10w40, 20w50 etc would seem risky, but the synthetics don't need as much polymer to reach that range.
 
Do what ever make you confortable. I switch one reg one syn, and when I run the syn I stretch the miles by one half.
 
BTW, I've been using Motorcraft 10W30 diesel-rated oil the last few summers. My thinking is that it is designed to stand up to the bearing loads from a high compression or charged motor. This summer I may go with the Motorcraft diesel 15W40 instead, since I'm hoping to thrash the car at 3 or 4 two day open-track events this season.

cheers
Ed N.
 
if you dont beat the crap out of your car 10W30 non synthetic will work fairly well from -10C to +30C if changed before it turns black, theres no magic oil out there or weight for these clearances :eek:
 
Double D's talked me into running the heavier weight moble 1 (15-50)
I had copper showing on my bearings ~90k.

Depending what the oil pressure looks like this summer (IA) I may drop down to 10-40, but I doubt it. My motor sees about 2-3X the level of abuse of Dalke's. ~15-20k a year, year around, lots of boost, spinning tires, daily driver.

The important thing is to change the oil. If running regular means you change it twice as much, ie 5k to 2.5k, then run regular.
 
My take

I'm on the side of Fast Ed N, David Neibert,XR7Dave and maybe some others here. I've read pro's and con's about oils for years from all the "experts" and haven't changed my mind about dino oil vs. synthetic. For the price of synthetic you can get 4 or 5 quarts of conventional oil. My opinion only is that you won't get better overall lubrication than from CLEAN conventional oil. I drive in similiar conditions as 95pearlbird (summer 120+ mostly highway), and from day one have used 10w-40 premium quality non-synthetic oil. I bought my 35th new and now have 163,000m on the clock with no teardowns. I just did valve cover gaskets and the engine and inside valve covers were perfectly clean. The oil pressure is still great (sender converted to read actual pressure). So for my money I'll stick with what has worked for me. John
 
Full synthetics have much better cold flow characteristics then conventional oils. Since most of the wear in the motor occurs during cold starting isn't it obvious why synthetics would help. Years ago I watched a small block chevy track motor being dyno'ed. It made about 600 HP. With just a change from Castrol to Redline the motor picked up over 20 HP. Then they drained it and replaced with Castrol to confirm and the 20 HP was gone. I use 15/50 Mobil in every vehicle I own including the motorcycles. The oil stays cleaner, every vehicle uses less synthetic then conventional oil and they never get dirty inside. The cold flow characteristics of a 15/50 synthetic is better then 5 wt conventional oils. The stuff works period. If you're using conventional oil try one oil change with synthetic. If you're unable to detect the difference in part throttle response, revability etc. I'll be amazed. Every engine I've put in I've been able to feel the difference.
 
I am running synthetic in both vehicles, I didn't see any improvement in power or fuel economy. But I do believe it is better. I change the oil about every 5K. I just happened to check the SC tonight. Boy is that oil black, I might have to change it sooner.
 
I agree I switched to mobil 15-50 synth. oil on my last oil change. That was the spring. Since then I have only put about 1000 miles on the car. Its a weekend and dragstrip only ride. I get better oil pressure cold and hot. It may just be me but I swear it winds up better to. I drive the car around a few miles when the weather is good to keep the battery charged up and to keep the tires from getting a set in them. This Spring I will have it changed again. I would run synth. in the trans and rear end if I thought it was ok. :)
 
I've been running Mobil 1 10W30 in my drag racer but have just switched to AMS Oil Series 2000 0W30. It has almost the same viscosity rating as the Mobil 1. No particular reason for the switch, just thought it might a bit better oil. I too had been advised to avoid the 30W difference but I don't really know if it's a valid concern. Didn't Dr Fred recommend 15W40?
 
When i got my SC i switched to Castrol 5w50 Full Syn. (get it at costco at a good price!) Also use the K&N High flow filter!
Car seems to like it alot!

For those of you who slack on your oilchanges because you dont drive alot or whatever, be mindful that the viscosity of the oil might not break down quite so easily, but the detegents and other things in the oil do! no catastophic failure would probably result though. just a little bit a info =)
 
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