I was shopping for motor oil the other day... Its time to change the oil in my truck, so I figured i'd get some oil and change the oil in my Fiero as well because its been a while since ive changed the oil in my Fiero.
Actually, I think ive put maybe 2000 miles on it in the past 8 years (but thats another story) and I think I only changed it twice.

I have heard that "conventional" motor oil loses its viscosity over time, or breaks down (if there is anything else that is bad please point it out).

I have also heard that if you use the "conventional" motor oil, you should not switch to synthetic.
My motor (SBC V8, was rebuilt and has less than 4000 miles on it since its rebuild) has only had Castrol GTX 10w30 for the approx. 4000 miles since its rebuild.

The reason I make this thread is because I would like to hear why it would be a good idea for me to switch to Synthetic motor oil (Mobil 1, specifically).
The car is NOT a daily driver. It is mostly driven to car shows, cruise-ins, and the occasional sunday drive. Will synthetic motor oil be a better choice for my car given its use?

Thank you in advance for anyone who has info to share!
Chris

[This message has been edited by chrishahn87 (edited 06-09-2011).]

as an auto mechanic, I do NOT reccomend using synthetic motor oil inside of engines with Flat Tappet lifters! Synthetic has been known to mess up flat tappets, make them stop spinning in their bores, and wipe cam lobes. Keep using conventional, or you MAY use a synthetic blend, just do not go full synthetic.

I have heared Mobil 1 is rated for flat tappets too but I do not trust in it :P. Synthetic has been designed for super lubrication, and engines with flat tappets need some friction (like automatic transmissions). I think they sell Zinc Additive (I personally have never looked but I know it exists out there) so if you go synthetic for its longer life and oil change intervals, add in a zinc additive, it will keep friction on flat tappet lifters and not cause the stuck lifter issue.

quote Originally posted by Racing_Master: as an auto mechanic, I do NOT reccomend using synthetic motor oil inside of engines with Flat Tappet lifters! Synthetic has been known to mess up flat tappets, make them stop spinning in their bores, and wipe cam lobes. Keep using conventional, or you MAY use a synthetic blend, just do not go full synthetic. I have heared Mobil 1 is rated for flat tappets too but I do not trust in it :P. Synthetic has been designed for super lubrication, and engines with flat tappets need some friction (like automatic transmissions). I think they sell Zinc Additive (I personally have never looked but I know it exists out there) so if you go synthetic for its longer life and oil change intervals, add in a zinc additive, it will keep friction on flat tappet lifters and not cause the stuck lifter issue.

Motor is a 1991 block and has hydraulic roller lifters, they were replaced with new when I installed Comp Cam at rebuild.
Is synthetic ok with roller lifters?

with roller lifters you are fine. they lifters do not need the friction to spin in the bore, since they are roller, they just slide up and down and are held in orientation by a retaining plate or bar. You would be perfectly fine to use any full synthetic oil in that engine.

quote Originally posted by Racing_Master: with roller lifters you are fine. they lifters do not need the friction to spin in the bore, since they are roller, they just slide up and down and are held in orientation by a retaining plate or bar. You would be perfectly fine to use any full synthetic oil in that engine.

Thank you!
What exactly are the differences between conventional and synthetic that would make me want to choose synthetic and pay the extra money?

I think Autozone has Mobile 1 and a filter on sale this weekend

with a flat tappet cam you need the zinc additive regardless. its not just a synthetic issue. I've fried a flat tappet cam myself on conventional, revving just to 6k (which I dont consider crazy high RPM) but since the car was boosted it felt like it was still making power, so I figured why not? didnt take long and all the exhaust lobes were literally gone

I run Castrol EDGE in my turbo 3.4. It is a flat tappet cam and I throw in a bottle of lubro moly high friction zinc stuff. It is safe to use with the high temps of the turbo.

I have been running this for the last couple years and drive the car hard with no problems. I use the full synthetic since the temps are higher and I do not want to roast anything. I can say the engine is clean as a whistle in there, no buildup whatsoever. On my next build though I will start with a roller cam block and get rid of the flat tappets once and for all. But I will not know about the cam till it either goes or I tear the engine down, neither option should happen anytime soon if all goes well.

http://valvoline.com/car-care/motor-oil-myths/

Mobil One chart with Zinc levels.
http://www.mobiloil.com/USA..._1_Product_Guide.pdf

This is what you need:

http://www.kirbanperformanc...%281%29+%237176.html

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84 2.5
87 328 GTB replica
87 Coutach replica

For the street Fiero this is what you need. Zinc 1100, Phosphorus 1000
http://www.liqui-moly.de/li...ng=e&voiladb=web.nsf

For the punished Fiero that sees road courses and endurance races needs the combination of these two: Zinc 1100, Phosphorus 1200
http://www.liqui-moly.de/li...ng=e&voiladb=web.nsf
http://www.liqui-moly.de/li...ng=e&voiladb=web.nsf

That is the combination I use in my Fiero.
http://a1.sphotos.ak.fbcdn....938_1176512507_n.jpg

Mobile One 15W50 oil is especially formulated for flat tappet applications. The lower grades who knows? However, my son has been using 5W30 Mobil one in his Olds Alero with a 3400 engine since new and has had no engine problems in 169,000 miles.
Synthetic oil is superior in that it doesn't break down under heat. It withstands the high heat usually associated with turbocharged applications whereas ordinary petroleum oil breaks down. Coking can be a problem in these engines and synthetic oil doesn't coke.. .

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Your engine is plenty new enough to switch to synthetic. I usually dont till around 10,000 miles though to make sure its broken in completely. You cant break a new engine in with synthetic. The biggest plus to synthetic is it dont break down as fast due to time and its also very resistant to heat which thins out regular oil the first hour you use it. I usually change my cars synthetic oil at 7500-10,000 miles. Ive had no problems at all. Since you can run it twice as long at least as regular oil, the double price dont mean anything. Car ive had that use a bit of oil (like a pint in 3000 miles) completely stopped with synthetic, which I attribute to it maintaining viscosity when its hot. The only real problem switching on a high miles engine, is some brands have aggressive solvents that will make it spout a lot of big leaks.

quote Originally posted by Racing_Master: as an auto mechanic, I do NOT reccomend using synthetic motor oil inside of engines with Flat Tappet lifters! Synthetic has been known to mess up flat tappets, make them stop spinning in their bores, and wipe cam lobes. Keep using conventional, or you MAY use a synthetic blend, just do not go full synthetic. I have heared Mobil 1 is rated for flat tappets too but I do not trust in it :P. Synthetic has been designed for super lubrication, and engines with flat tappets need some friction (like automatic transmissions). I think they sell Zinc Additive (I personally have never looked but I know it exists out there) so if you go synthetic for its longer life and oil change intervals, add in a zinc additive, it will keep friction on flat tappet lifters and not cause the stuck lifter issue.

If the lifter is not rotating it is because the cam is worn out. Lifter rotation is induced by camshaft not by any oil type. The hydraulic flat tapped cam is designed to make the lifter rotate.
Like the colleague said, regardless of the oil you need Phosphorus and Zinc for the flat tapped cam. Synthetic has a much greater advantage over conventional oil; it keeps your engine clean, no coke build up, can withstand a lot of heat and they can last a long time.
Just be careful of the claims on the 10,000 and 15,000 miles extended interval oils. Take Castrol Edge and Mobil 1 Extended for example. The bottles say they can last for 10,000or 15,000 miles and then there is little red asterisk right next to that sentence. If you look at the back of the bottle right next to the asterisk it says: "If vehicle is driven in dusty places, prolong idling, towing or hauling and racing; do not follow these recommendations. Well? Aren't those conditions what almost every car in America goes through?

quote Originally posted by Racing_Master: as an auto mechanic, I do NOT reccomend using synthetic motor oil inside of engines with Flat Tappet lifters! Synthetic has been known to mess up flat tappets, make them stop spinning in their bores, and wipe cam lobes. Keep using conventional, or you MAY use a synthetic blend, just do not go full synthetic. I have heared Mobil 1 is rated for flat tappets too but I do not trust in it :P. Synthetic has been designed for super lubrication, and engines with flat tappets need some friction (like automatic transmissions). I think they sell Zinc Additive (I personally have never looked but I know it exists out there) so if you go synthetic for its longer life and oil change intervals, add in a zinc additive, it will keep friction on flat tappet lifters and not cause the stuck lifter issue.

I have been using Mobil 1 in my 86 SE 2.8 for 5 years now, with no problems at all. It's an automatic, so I also use Mobil 1 ATF, and grease the bearings and ball joints with Mobil 1 grease. Everything works perfectly.
My other Fiero's a 5-speed, so it's transmission gets Amsoil synthetic synchromesh.

I've run Mobil One 10-30 and 10-40 in my 86 SE for the last 135,000 miles. It now has 165,000 and runs like new.

quote Originally posted by TopNotch: I have been using Mobil 1 in my 86 SE 2.8 for 5 years now, with no problems at all. It's an automatic, so I also use Mobil 1 ATF, and grease the bearings and ball joints with Mobil 1 grease. Everything works perfectly. My other Fiero's a 5-speed, so it's transmission gets Amsoil synthetic synchromesh.

Well mobile one is the only brand i would consider to use.

Been using Mobil One for years in all my cars.

Syn oil just is more duable to breakdown and temps also cold start up the oil is not as think and give better lub at even very cold temps at the first fire up. It will not be long all new cars will be in syn oil. Right now many already are on it most are using Mobil One.

The cam issues most people see are due to people not using the breaking lube to break in the cam. THis is where the zink is important. Most Cam companies are fine with syn oils no matter the tappet. Also many people screw up the valve train geometry and also wipe the cam out. Note I deal with warranties on all Major MFG of performace cams. Very few cams fail due to a bad cam just mostly poor install and break in. Note too many lifters are installed in bores that will not let them spin as no one ever checked them.

The fact is you can change to syn oil in any engine in good condition. Note the one negitive side effect is that the older engines are not sealed up as well and there is the ability for the oil to leak more easily. The molecular make up of a syn oil is smaller and this can let oil leak from places the larger dino based oil will not leak from.

Today racers and high end performance cars do not use syn oil because they are paid to they use it because it is the best product out there today.

My observations and opinions for what they are worth:

I have never heard of synthetic causing trouble with tappets. I have heard of the lower zinc content in all oils causing a problem with wrecking lifters. Actually, fairly well documented.

I have switched from conventional to synthetic on an early 90s motor and after a few months almost all the gaskets started leaking...a lot. Most people would tell you this is a myth, I can tell you it happened to me!

Mobil 1 has changed their synthetic base and or their detergents in the last few years. This was to make the price lower...hence why you can by it for $3.50 a qt at Walmart, not the $6+ that it used to cost.

I started putting Amsoil in all my cars in the last 12 months. Changed oil and trans fluid (6spd) in my 05 GTO and picked up 2mpg in fuel mileage. Would Mobil 1 do the same? Maybe...,my experience was with Amsoil. No, I'm not an Amsoil dealer either.

Honestly, I think the best thing you can do when it comes to oil is install a very high quality filter. If you have anything that says FRAM on it, throw it in the garbage. Do your research online, but WIX is a good quality alternative to cheap low quality filters available in most stores.

quote Originally posted by Racing_Master: as an auto mechanic, I do NOT reccomend using synthetic motor oil inside of engines with Flat Tappet lifters! Synthetic has been known to mess up flat tappets, make them stop spinning in their bores, and wipe cam lobes. Keep using conventional, or you MAY use a synthetic blend, just do not go full synthetic. I have heared Mobil 1 is rated for flat tappets too but I do not trust in it :P. Synthetic has been designed for super lubrication, and engines with flat tappets need some friction (like automatic transmissions). I think they sell Zinc Additive (I personally have never looked but I know it exists out there) so if you go synthetic for its longer life and oil change intervals, add in a zinc additive, it will keep friction on flat tappet lifters and not cause the stuck lifter issue.

More mis-information in this post than I have the patience to de-bunk.

quote Originally posted by La fiera: "If vehicle is driven in dusty places, prolong idling, towing or hauling and racing; do not follow these recommendations. Well? Aren't those conditions what almost every car in America goes through?

I guess I'm in the minority because my Fiero is not driven in dusty places, does not prolong idle, and I certainly don't tow and haul with it. [/sarcasm]

I think most cars today could be perfectly safe with longer oil change intervals. That 3,000 mile stuff is from the 60s.

quote Originally posted by KurtAKX: More mis-information in this post than I have the patience to de-bunk.

I agree, even though I'm not certified as an "auto mechanic" lol..

If you ever have the chance to look at the certification tests you will be astonished at how simplistic they are.

It is pretty laughable.

quote Originally posted by rogergarrison: You cant break a new engine in with synthetic.

Did you let all the car manufacturers know that? You could be saving them hundreds of thousands with warranty work!

Is it true that new engines need break-in periods using conventional motor oil?

That is a myth. In the past, engine break-in was necessary to remove metal flashing or any other abrasive material left inside the engine after machining, as well as to allow the valves and rings to "seat" properly. Today's engines are built with much tighter tolerances, much improved machining, and under much cleaner conditions compared to the engines of 10 or 20 years ago. Current engine manufacturing technology does not require a break-in period using petroleum-based motor oils.

http://www.mobiloil.com/usa...il_1_faqs.aspx#FAQs4

Synthetic oil is fine, I used it in my Fiero and never had a problem.
The only thing I would not use synthetic in is my Rotary but that is for different reasons.

quote Originally posted by jscott1: I guess I'm in the minority because my Fiero is not driven in dusty places, does not prolong idle, and I certainly don't tow and haul with it. [/sarcasm] I think most cars today could be perfectly safe with longer oil change intervals. That 3,000 mile stuff is from the 60s.

This is true. 3,000 miles is the worst case for oil.

Today syn and non syn oils can easily go 7000-10,000 miles.

GM on their new vehicles has a oil life gauge like BMW and these things really are accurate. Engines are much better today as in most cases oil is much better [accept for the Zink issue] in many ways. People today just don't appreciate how much better things like Oil and Tires are today since they never had to deal with the old one's. It was not that long ago you were lucky to get 15,000 miles or less on old Bias tires.

Anymore with the kind of driving we do the new cars I own don't get to 20% oil life till 8,000 miles. I ten to change it between 20-10% so I don't go over.

It should be noted that the most popular synthetics like Castrol, Mobil 1, Penzoil and Chevron are oils that are synthesized from modified petroleum components but not crude oil. They have improved properties of standard oils but without the tendencies to gel or gum when used in an engine environment. They also have a much higher temperature tolerance before breaking down, a concern in turbocharged engines.
I am told that the more expensive synthetics like Royal Purple and Amsoil are slightly different in that they add more high temperature additives

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

quote Originally posted by KurtAKX: More mis-information in this post than I have the patience to de-bunk.

X3. And while well intentioned, many of the follow up posts in this thread are not that much better. So much misinformation!

For the best discussion I've ever seen for a general audience, see Motor Oil University, a series of articles by A.E. Haas. The link has been posted several times before on PFF, but it's well worth repeating here.

[This message has been edited by Marvin McInnis (edited 02-27-2012).]

quote Originally posted by Marvin McInnis: X3. And while well intentioned, many of the follow up posts in this thread are not that much better. So much misinformation!

The first sign of trouble with a post is when you see "I Heard".

Many of the failed cams I deal with are due to I heard or my Buddy is a mechanic and he told me.

My favaorite is when I ask how did you break it in. Then they tell me we took it up on the 4 lane and hit a lick. The other is it had a soft lobe?. Even when the entire cam is made of the same metal forging?

I don't like synthetic oil in older engines for two reasons....

1. The low viscosity that is available doesn't support adequate bearing load. 5w-30 is about one step above 3 in 1 sewing machine oil.

2. It's almost guaranteed that you will develop oil leaks at the front and rear main seals.

Some of the questions from my experience or people I know.

Breaking in an engine requires some wear on cylinder walls and rings to seat them properly. Synthetic oil is 'too good' to allow it to happen.

Mobile One has the most aggressive solvents of any and does cause leaks in older worn engines when swapped for dino oil. Most are front and rear seals, some valve cover and pan gaskets.

Most owners manuals specify (at least ones Ive read) 7500 miles between oil changes except in what they even term SEVERE USE cases. towing, idling, dusty conditons. Most of the country doesnt have any of those. And thats with reg dino oil.

Some manufacturers prerun engines to break them in before they ever get to a car. Lincoln at one time even drove new off the assembly line cars around a high speed test track to break them in, then disassembled the engine and checked things like cyl walls and bearing surfaces to make sure everything was right. Only after reassembly did they ship the car out for sale. That was mostly the early Mark ( II & III) models.

....and since when did any manufacturer car about their car living a long life . They would love it if every car they sold blew up a week after warranty expired. They make more off parts and service than they ever will selling the car. I dont want any new car with synthetic in it. I use the old proven method of driving it an oil change or two on dino, THEN switching.

I would never switch to Mobile One on an older engine unless its got a record of great upkeep. Your just asking for oil puddles in the garage. Its not that its bad, it just disolves all the hardened up goop around 125,000 mile engine seals thats keeping it from leaking. I dont know one that switched to it that didnt. I use Castrol and I havent had any leaks that werent already leaking.

quote Originally posted by rpro: I don't like synthetic oil in older engines ...

That's legitimate. No one here is trying to tell you what you should be using in your engine. The credibility of advertising by oil manufacturers and vendors, who most certainly are trying to influence your choice, is another matter.

quote for two reasons....

But this is what I find frustrating. One of your reasons is totally bogus and the other is only partly true. Such misinformation, even when well intentioned, doesn't help anybody.

quote 1. The low viscosity that is available doesn't support adequate bearing load. 5w-30 is about one step above 3 in 1 sewing machine oil.

A 30 grade synthetic will fall into the same viscosity range at engine operating temperature (~100 C) as a 30 grade conventional oil. Viscosity at 100 C is a physical property of the oil; it has nothing to do with synthetic vs. conventional. Again, I refer you to the Motor Oil University link as a valuable source of good, unbiased information.

Surely you're not suggesting that the GM engineers didn't know what they doing when they specified 5W30 oil for an engine they designed?

quote 2. It's almost guaranteed that you will develop oil leaks at the front and rear main seals.

Synthetic oils do tend to leak from some engines that do not leak appreciably on conventional oils. It's a side effect of some of the otherwise desirable properties of synthetics. However, I currently have two vehicles with more than 150,000 miles on the engines running Mobil 1 High-Mileage synthetic, and any leakage is minimal. The Dodge Caravan 3,3 has 245,000 miles on the original engine, and I've always run Mobil 1 10W30 in it. The front main seal began leaking at about 200,000 miles. Before paying to have the seal replaced, I figured that trying the 10W30 Mobil 1 High-Mileage oil (which apparently contains seal softener/expanders.) would be worth a try. The front main seal stopped leaking within 2000 miles of the change. The other car is a Buick Regal 3.8 engine that had run conventional 10W30 oils (mainly Valvoline) or synthetic blends most of its life. The engine remained tight and leak free after I switched it over to Mobil 1 High-Mileage 10W30 at about 140,000 miles.

quote Originally posted by rogergarrison: I dont know one that switched to [synthetics] that didnt [develop leaks].

Now you do.

[This message has been edited by Marvin McInnis (edited 02-27-2012).]

I know a couple now apparently if your to be believed... Of course we dont know the history of your engine either. Your engines could have been in great shape. Ive Have had cars with 200K that got excellent care their whole life. I know others that are junk after 15K.

I run full synthetic in all my cars, there is no reason not to switch. I've notice a 3mpg increase in mileage, they are better for cars that don't receive oil changes every 3 months, and you also don't have to change your oil very often, 10,000miles on most cars 5,000 miles on turbo's. Just please note, do not break in an engine on synthetic oil, it does not have the friction required to properly seat piston rings.

quote Originally posted by rpro: I don't like synthetic oil in older engines for two reasons.... 1. The low viscosity that is available doesn't support adequate bearing load. 5w-30 is about one step above 3 in 1 sewing machine oil. 2. It's almost guaranteed that you will develop oil leaks at the front and rear main seals.

Syn oil is available in other viscosities and levels of oil demands.

It will not develope a leak it may leak a little more but the leak is aready there if it leaks anything. They do have oil for higher mileage engines and it is a little less prone to leaking more.

If you don't want to use it in an older engine that is fine but it will not damage an older engine.

quote Originally posted by rpro: 2. It's almost guaranteed that you will develop oil leaks at the front and rear main seals.

I replaced the front and rear seals on my indy and put in 10W40 and it still leaks like a stuck pig. Imagine synthetic in there? Well I switched to synthetic blend for high mileage engines. I think the seals stopped leaking. Now only to fix those valve cover gaskets... frickin Iron puke engine!

[This message has been edited by jscott1 (edited 02-27-2012).]

Since this thread is related to my current project, I have a question for you guys that know your stuff:

I'm currently in the process of overhauling a Duke with ~85K on it (Don't bother telling me I'm wasting my money. This is for a car I am keeping mostly stock), and was wondering what the suggested route to take is. ALL seals/bearings will be new, has a freshly machined head, and will even have a freshly machined crank (has a few .001"+ gouges in one of the bearing surfaces), and possibly cam (depending on how bad the cam is).

From what I'm reading, I am best off using regular motor oil for the first 2 oil changes, then swap to synthetic, to avoid coking the pistons/internals (I plan to keep the car many many years, especially after all the $ I have put into it), and add this: http://www.kirbanperformanc...%281%29+%237176.html

I just read on a website that:
"However, roller tappets can be re-used, where as flat tappets cannot not be re-used. If you tear down your engines frequently, the rollers can be used over and over again provided they are not damaged or show signs of wear."

Does this mean I need to replace my lifters before I re-assemble the engine? I'm still at least 2 weeks away from doing that, fortunately (need to get everything hot tanked and machined).


Thanks,
Brian

quote Originally posted by Bstrickler934: "... flat tappets cannot not be re-used."

That statement as quoted, without further qualification or explanation, is just flat wrong. I would agree that if you install a new camshaft you should also install new lifters.

quote Does this mean I need to replace my lifters before I re-assemble the engine?

Not necessarily. First, the old lifters must be kept paired with their respective cam lobes. If the lifter faces and cam lobes are in good condition (no measurable or visible wear other than slight polishing) and if you have kept the lifters and cam lobes matched, then it is probably safe to reuse the old cam and old lifters. Use plenty of assembly lube on the cam lobes and lifter faces. Pre-lubing the engine prior to first start helps to ensure an immediate supply for fresh oil to the entire valve train.

[This message has been edited by Marvin McInnis (edited 02-28-2012).]

quote Originally posted by Marvin McInnis: Not necessarily. First, the old lifters must be kept paired with their respective cam lobes. If the lifter faces and cam lobes are in good condition (no measurable or visible wear other than slight polishing) and if you have kept the lifters and cam lobes matched, then it is probably safe to reuse the old cam and old lifters. Use plenty of assembly lube on the cam lobes and lifter faces. Pre-lubing the engine prior to first start helps to ensure an immediate supply for fresh oil to the entire valve train.

Thanks man. I'll have a look at the lifters, and see if they're still good. Hopefully I don't have to buy new ones.

I know all about using assembly lube. I have a whole giant tube of it from when I re-did the head on my bike. I figure it wont hurt too much if I use a little extra lube on it.

If the lifter faces have a slight inverse dome, then I should replace the cam and lifters, right?