synthetic oil in sbf
- Thread starter pazur
- Start date
i have used synthetic oils in a number of engines, and i can tell you from experience that you gain longevity, and in most cases fuel economy also. understand however that if you had an oil leak that seemed to go away with time, the leak is still there and it will be found with the synthetic oil. this is due to the synthetic oil's cleaning ability. you wont notice any improved performance, unless you have it on a stop watch, but you may notice the engine running smoother after the switch. if you drive a lot of miles, i say make the change.
coolblue65
Founding Member
As already stated, it is a better product, I use it in my mustang and my vette (all vettes come with Mobil 1 from the factory).
Downside is it cost 2 or 3x as much and will definately find any leaks that you may have, for example if you have an occasional drip, it will turn into numerous drip.
That being said if your motor is mild and hasn't been rebuilt recently, I would stick with regular oil.
Downside is it cost 2 or 3x as much and will definately find any leaks that you may have, for example if you have an occasional drip, it will turn into numerous drip.
That being said if your motor is mild and hasn't been rebuilt recently, I would stick with regular oil.
on a fresh build or recent build with not a lot of miles i'd go to the synthetic, if it's the original engine and has never been rebuilt, don't use the synthetic just keep using you standard oil. also don't use quaker state or penzoil in anything, even your lawnmower, i use only castrol or valvoline conventional oils in my stuff. i'll soon be switching to valvoline synthetic in the stang since it's about ready fo it's first real oil change and has about 1500 miles on it, plus lot's of driveway time too.
Hack
15 Year Member
Some people say not to use a synthetic with a flat tappet cam, because it's possible for the lifters to not spin properly if there isn't enough friction. It's interesting to see a couple posts of people with no problems.
it depends on the oil. i used Castrol Syntec when it first came out in the Stang's old motor and wiped a lobe on the cam, this was with about 30k on that motor but the reason it wiped it, i think, was because of the viscosity, i used the 5w-20 that was really all that was available when Syntec came out. i'll use valvoline 20w50 this time around.
I ran it in my '68 after I'd had about 5k miles on the engine. You can't run it on a freshly rebuilt motor, it will inhibit break-in, nor is it a good idea to switch to it later in life. Not only will it find leaks, as previously mentioned, those same detergents can sometimes break loose chunks of sludge and block oil passages. Not good.
All that aside, if you can, RUN IT! The It probably will, as noted, run smoother and more efficiently, and I noticed felt like it had a smidge more torque. Plus you get much more mileage between oil changes. Some special formulas like AmsOil has actually claim 25k miles between changes; on "regular" synthetics (in my case, Mobil1), I change on ~5k-7500 intervals, changing the filter every time.
All that aside, if you can, RUN IT! The It probably will, as noted, run smoother and more efficiently, and I noticed felt like it had a smidge more torque. Plus you get much more mileage between oil changes. Some special formulas like AmsOil has actually claim 25k miles between changes; on "regular" synthetics (in my case, Mobil1), I change on ~5k-7500 intervals, changing the filter every time.
Synthetic is a much better product than conventional oil. I would agree that you may want to think twice about using it on a high milage car if you started with conventional. I completely disagree with the comment that it is more expensive. Quite the opposite.
Lets say we both own the same car which takes 5 quarts of oil at each oil change. We each drive 15,000 miles a year. You buy conventional oil @ $4.00 per quart. That's $20 per oil change. At 3000 miles inbetween changes you will change oil 5 times a year. You use 25 quarts of oil at a cost of $100. If I spend $8.00 per quart each change will cost me $40. At a 10,000 mile interval I change my oil 1.5 times a year. I use 7.5 quarts at a cost of $60. I win on price and recycling. If we pay to have our oil changed the difference is even larger.
Lets say we both own the same car which takes 5 quarts of oil at each oil change. We each drive 15,000 miles a year. You buy conventional oil @ $4.00 per quart. That's $20 per oil change. At 3000 miles inbetween changes you will change oil 5 times a year. You use 25 quarts of oil at a cost of $100. If I spend $8.00 per quart each change will cost me $40. At a 10,000 mile interval I change my oil 1.5 times a year. I use 7.5 quarts at a cost of $60. I win on price and recycling. If we pay to have our oil changed the difference is even larger.
jerry S
New Member
It is because the synthetic oils do not have the zinc and magnesium additivesthat a flat tappet cam needs. Shell Rotella T might be the only synthetic oil you can use on a flat tappet cam because it is supposed to have enough zinc and magnesium in it to safely use with flat tappets.
Also, there are zinc additives you can, well, add like SciTech or STP containing ZDDP
Here is a note on it by Crane Cams http://www.compcams.com/information/whatsnew/NewsDetails.asp?ListHistoryID=1821071676
Hack
15 Year Member
Actually that's a whole separate problem (the lack of heavy metal lubricants) - and that is true of most modern oils.
Shell has changed the formula for Rotella T as of January this year I believe. edit - now it doesn't have the ZDDP any more.
http://www.network54.com/Forum/1194...R-1+Racing+Oil,+NSL++oils++.+Good+Info+Here+!
There's a link to some info about Valvoline VR1 racing oil that is supposed to be off road only and doesn't meet the newest standards for pollution reduction.
jerry S
New Member
reenmachine
20+ Year Stangneter 
Well, you've got some other issue then. One revolution of the engine is going to make the rear wheels turn the same amount regardless of what type of oil is in the engine.
what Reen said. the only way i could see that would be if the engine was really struggling to keep that rpm before and didn't have to work as hard after, could also be that the trans may have been a quart low on fluid and was slipping, assuming the car had an auto trans or the clutch was slipping if a manual trans.
the engine working harder would be an extreme case and would most likley indicate that there was internal engine problems.
the engine working harder would be an extreme case and would most likley indicate that there was internal engine problems.
reenmachine
20+ Year Stangneter
I use Amsoil exclusively and have found this to be true. I put the highest-grade Amsoil in a V6 Nissan 350Z after about 3k mi. break in (along with an Amsoil filter) and proceeded to drive 21,000 hard, abusive miles in about 8 months without touching it. I then sent a sample of the used oil to an independent testing lab and it came back almost perfect. The report basically said to think about changing it soon, but no big hurry. It probably would have gone the 25k miles just fine had I not chickened out. I picked up about 2 mpg as well.
I have a Chevy 2500HD with the 6.0L gas engine. I switched to the same Amsoil after 6600 miles and picked up an average of 1 mpg. Maybe that doesn't sound like much, but in this truck it's about a 9% improvement.
Pete, are you sure the 2 mpg gain in the Z was from the Amsoil and not just the engine breaking in and loosening up? it's not uncommon for a new car to pick up a few mpg after break in of the first 10-15k. just wondering if you considered that
reenmachine
20+ Year Stangneter
I understand what you're saying, but it was basically a sudden change when I changed the oil, tested over identical long-term conditions. Basically, I drove from LA to Florida, changed to Amsoil, and drove back. 2500+ miles each way, similar weather, same average speed, etc.
Also, I've observed mpg improvements in every vehicle I've used it in. Ranger, F150, 1-ton van, 2500HD, 350Z, CR-V, Explorer.
I'm not a super Amsoil evangelist or anything, but I like the stuff and have seen consistent results.
that's not true, an engine has no memory of what oil has been used in it and it makes absolutely no difference what you oil you use as long as it is a good oil. i don't like quaker state because it's parafin based, i don't really want to use WAX to lubricate my engine, not sure about you, anyway, the point is as long as use a good QUALITY oil it doesn't matter. that said, if the engine has high mileage and has been run on conventional mineral based oil it's not a good idea to switch to synthetic, i'd say anything more than 75-80,000 miles, now if the engine has been run on synthetic all it's life then it doesn't really matter how many miles it has on it.
brianj5600
Active Member
I think my next oil may be Mobil1 motorcycle oil. It has a good additive package for metal to metal protection like a flat tappet cam. It is formulated to protect the transmission gears.
I have noticed a change in fuel mileage with Mobil1. I track mileage as a way of monitoring the health of the engine. Synthetic bumped miles per take up by about 35 miles on a 16 gallon tank so it is about 2 mpg. I sold one car to a good friend and he decided to save some money and use conventional oil only to find out that he lost those 35 miles per tank. He switched back next oil change and gas mileage came right back. I think you save money using synthetic oil because of gas savings and extended drain intervels.
I have noticed a change in fuel mileage with Mobil1. I track mileage as a way of monitoring the health of the engine. Synthetic bumped miles per take up by about 35 miles on a 16 gallon tank so it is about 2 mpg. I sold one car to a good friend and he decided to save some money and use conventional oil only to find out that he lost those 35 miles per tank. He switched back next oil change and gas mileage came right back. I think you save money using synthetic oil because of gas savings and extended drain intervels.
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