im doing an oil change today and i wanna go synthetic what is the best oil to use,and im using a fram double guard oil filter should i get a new one or are there better filters out there.Will slick 50 oil treatment work with synthetic oils.

------------------
1987 Trans AM GTA
305 5SPD
Hypertech airfoil
gutted maf
kn filter
High Flow Cat,
3"Walker pipe
Dynomax Super turbo Muffler
TB Coolant bypass

[This message has been edited by Stormshadow GTA (edited July 04, 2001).]

 

Well this question is very opinionated. I know that in the new corvettes and camaros they put in Mobil 1 synthetic. As for filters you could spent a lot of money on anything from a K&N oil filter to a cheap regular AC filter. Delco does sell a filter only found at Pep Boys and Carparts.com that is called UltraGuard Gold. It has synthetic filtering media inside, and a teflon coating on the surface that threads. Supposedly this filter is the best AC sells. So it's up to you what you want to do.

 

Mobil 1 is all I use. Second choice is Red Line and third choice is Amsoil.

------------------
86 SC, 305 LG4, TH700R4, SLP headers, 3" cat and exhaust. Mild cam 204/214, .423/.442. SLP shift kit, richmond 3.73's w/limited slip. Suspension Techniques Sway Bars, Globel West Wonderbar, Poly everything bushings, Metco LCA's, Lakewood Panhad Rod. 16" ROH, with Toyo 245's. For autocross, 16" IROC's w/bfg R1's... Nothing easy can be fun...

 

My personal preference is for Mobil 1, but they're all better than dinosaur juice. I don't think you can go wrong as long as you use an all-synthetic, not a "blend".

Slick 50 is not a good idea. I'd skip that.

Lose the Fram filter, it's garbage. Get a regular AC/Delco PF-35, or a PF-35L if you want synthetic filter medium, or PF-1218 if you want an anti-drainback valve.

------------------
"So many Mustangs, so little time..."
ICON Motorsports

 

I decided to go for Mobil 1 tri synthetic and a KN oil filter.

------------------
1987 Trans AM GTA
305 5SPD
Hypertech airfoil
gutted maf
kn filter
High Flow Cat,
3"Walker pipe
Dynomax Super turbo Muffler
TB Coolant bypass

 

Mobil 1

No slick 50 ever

One thing to keep in mind, if you have a small oil leak with dino oil, it will be bigger with synthetic....ask me how I know

------------------
ASE Mechanic/Machinist/Smog Tech

1999 NBM Trans Am
1986 Chevy 3/4 ton pick up
1981 corvette
1995 Kawi ZX6R
and 2 POS commuters...

R.I.P. #3
"He can see air"

 

I prefer Mobil 1, and I think Purolator Pure One filters are pretty good for the money. Stay away from Fram and definitely avoid any oil additives no matter what some dope tells you. Just my $0.02.

------------------
1990 IROC 350
Mods: Too busy trying to make it run right to mod it.
Airfoil, Dynomax cat-back, Accel coil, 180 t-stat, Bald Eagle tires,
Hypertech fan switch, Accel 23# injectors, Holley AFPR, ported plenum,
Ruger P95DC, hot wife, new oil filter, thick rubber floormats.
18.0 @ 85MPH since I'm one big-a$$ MF
"It's better to have and not need than to need and not have."

 

Mobil 1 is very good oil, a top rate synthetic for the price. Royal Purple is also good, but it's hard to get at a decent price(unless you happen to live in Humble, TX and can drive to the factory and buy it there.. only live 60 miles away.. funny how that's still just the OTHER SIDE OF TOWN!!!!!!.)

I used to use Fram filters.. and Fram only.. until I started seeing a DISTURBING # of them crack the casing, have the filter material sucked out of the little metal guard that holds it in.. that was just when I worked at O'Reilly's.. when I went to work at a real shop.. I saw more of the same.. so I stopped using them on any of my vehicles. On my dad's Galant I use WIX filters, my mom's Civic gets Honda filters, and my Camaro gets a AC Delco PF1218. I personally use Castrol GTX 10W30 in my car(and my dad's).. and Castrol GTX 5W20 in the Civic. But when I decide what I want to put in the Camaro(a few years from now) I'll run the first 500 miles or so w/ Castrol and Mobil 1 from then on out.

Anthony

p.s stay away from oil additives.. I wouldn't ever use them. a lot of times they do more harm than good.

------------------
previous ride: 87 Camaro LT
350, A4.Comp Cams 268H, Edelbrock Preformer intake, Hedman Headers and y-pipe, gutted cat, No AIR/smog pump. 14x3" Open element K&N, Q-jet w/ D hanger and DA rods, adjusted AV spring tension and quick can.

Current ride: 1992 Camaro RS, K&N, Flowmaster, 305, T5, Black, T-tops, 76k miles.

 

I used to work in a lube shop, and we used to do multiple tests on our oils frequently. We found that, of the synthetics, the Mobil 1 held up best for the viscosity/bearings tests and the heat tests. 90% of the synthetics we tested were very acceptable, and would show very little difference on a street engine. The only synthetic I would shy away from would be Quaker State. There was a high detergent content that makes high temp operation iffy.
I use Mobil 1, but if you can find a reputable name brand for cheaper, it's probably fine.

------------------
No guts, no glory.

 

What is the recomended life span of synthetic oil, 3 months or 3000mi? I was just wondering if it is worth the extra money.

 

They say Mobil 1 is good for 7500 miles or more.....

I do oil and filter at every 3000 Mi. (Mobil 1)

Trans fluid and filter every 15000 miles. (Mobil 1 synthetic ATF)

Fuel filter every 6 months.

Rear end every 12 months.

Coolant flush once a year.

Some of my friends think I'm overly **** about this stuff..

------------------
ASE Mechanic/Machinist/Smog Tech

1999 NBM Trans Am
1986 Chevy 3/4 ton pick up
1981 corvette
1995 Kawi ZX6R
and 2 POS commuters...

R.I.P. #3
"He can see air"

 

You can't go wrong with Mobil 1 oil, I have been using it since my car had 5000 miles on it, It has 140,000 on it now and doesn't burn or leak a drop, and I change it every 8 to 10 thousand miles.

------------------
92 Camaro RS 5.0 5-Speed(Quasar Blue)
14" Open Air Cleaner
3.08 Posi-trac
Edelbrock TBI Intake
Crane cam
Ported & polished stock heads 3 angle valve job
HyperTech Chip
SLP Headers (Ceramic Coated)
UltraFlo cat-back exhaust

74 Dodge Dart Sport 360 (11.2 1/4 mile)

2000 Dodge 1500 Ram Sport

 

There is a lot of debate about this topic. I happen to use Mobile 1 because is it easy to find. With regards to filters, I think Fram is one of the worst! Just feel how light they are! There is no filter material inside. I use the Mobile 1 filters as well. They are nice and have a great gasket. I change my oil every 3000 miles. Here is why. Think about why you change your oil. You change it for one reason. No not because of any breakdown or anything. You change it because it gets dirty! If you don't change your oil enough, your engine gets dirty and that leads to problems. Change your oil every 3-4K miles and you will be ok. Personally, I check my oil and when it starts looking dirty I change it. There is no reason why a sythetic oil would not have to be changed as much as conventional oil. That is my opinion.

 

Okay, I've had enough now. Let me set the record straight: YOU CHANGE CONVENTIONAL PETROLEUM OIL EVERY 3000 MILES BECAUSE IT GETS DIRTY FROM BREAKING DOWN (oxidation of the base lubricant and additives)! Secondary causes are air injested dirt and combustion products. With good air filtration, synthetic will not get as dirty because it is less prone to breaking down (at least that applies to Mobil 1 and AMSOIL, I wouldn't paint with that broad brush for the "me-too's" out there such as the aforementioned Quaker State or Castrol).

As for drain interval, using their air and oil filters, AMSOIL recommends 25k (35k with their top of the line oils) or 1 year oil changes, with an oil filter change half way through that. I've been following that recommendation for 18 years, and haven't yet worn out an engine. Mobil will say 25k or 1 year after your warranty expires (chickens!). Not sure what Redline or Royal Purple say. Everybody else just wants to sell you a more expensive oil just as often.

Yes, it is hard to keep opinions out of it, but you should at least have some idea of the chemistry and physics before spreading yours. Not using Slick additives is not an opinion - don't do it if you expect the oil manufacturer to back their product (that's a broad brush I'm willing to use).

------------------
82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/'87 LB9 block, ZZ3 cam and intake, World 305 heads, Hooker headers & y-pipe, 3" Catco cat & 3" cat-back).
57 Bel Air, my 1st car. '66 396, 9.7 CR forged TRWs, Weiand Action+, Edelbrock 1901 Q-Jet, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 600 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).

 

Five7,

I've long heard about the extended interval with Amsoil (considering using it in my tractors and forklifts, etc, that don't get a lot of attention throughout the year).

But I've never heard of a claim by Mobil 1 for extended operations....can you point me to some "authentic" M1 literature? All I've ever seen put out by M1 says to consult your owners manual.

 

Oh, another thing (to Five7), your comment about waht causes oil to get dirty (if I understood you correctly) and air intake being a primary cause...I tend to disagree from my observations, I tend to thihnk it has more to do with the combustion process than air intake (in normal driving conditions..i/e, maybe not living in a dustbowl??).

One of my foklifts is propane powered, we only change the oil every couple of years as a precaution to it breaking down...it's always a clean as a whistle...I mean looks like it did when it came out of the bottle, our other lift is carb'ed and get's top looking like any automobiles oil after time, we use both of them equally in the same conditions, neither burns/uses oil.

Another thing that leads me to believe the oil contamination is more due to combustion by-prodcuts than air ingestion is that I just bought a 2001Import vehicle (Manufacturers name withheld due to obvius flaming that would come) and it qualifies as an ULEV, owners manual recommends 10K changes (dino oil) or 5K chages under severe duty operation.

Just my thoughts...

Oh, and relevant to the original post, I use M1 in my IROC

 

I agree with Mike. I was taught and believe that the by-products of the combustion process, that enter the oil via blow-by past the rings (because we all know that even a gapless ring will allow some blow-by don't we), are the main reason why oil needs to be changed as often as it does. The oil itself can only suspend so much soot and carbon from the combustion process before it becomes 'saturated' with contaminents. Look at a diesel engine for instance; their oil turns black immediately from the huge amounts of soot that come from the combustion process of a high compression ignition system. And the reason why the manufacturers have severe duty recommendations follows this logic as the dirtier the environment is and/or the harder the engine pushed, the sooner the oil will become 'saturated' with contaminants and need changing.

So the use of synthetic oils will not extend the length of time (or mileage) between oil changes since the amount of oil in the crankcase is still the same and cannot suspend any more contaminants than conventional oil.

BUT... the main advantage of the synthetic oil is the durability. The actual viscosity and lubrication properties of a synthetic oil do not degrade like a conventional oil's will when subjected to high amounts of stress. Synthetic oils maintain their designed properties even when subjected to extreme heat and high sheering forces.

So in a perfect world the synthetic oils would create a longer oil change interval since they do not 'break down' as quickly as conventional oils.

Just for the record I use Mobil 1 in my 'nice' vehicles (once they are broke in of course) and whatever is cheapest in my beaters. I change the oil every 1500 to 2000 miles in the cars that I drive really hard - regardless of the type of oil it has in it. Just remember that even if the oil is pricey - it is cheaper in the long run.......

Matt.

GM Certified Tech.
ASEP Graduate

------------------
1987 GTA L98 MD8 GH3
355 '97 Vortec 4-bolt block, TRW(suck) forged pistons 10:1 CR, TFS 23*, LT4 Hot Cam, Ported plenum and intake, SLP Siam Runners, Edelbrock TES, gutted Cat, Flowmaster, K+N cone, AFPR, TB bypass, AirFoil, !AIR, !A/C, !EVAP, ARAP, 2300 stall, Hotchkis STB.

 

Well, I was going on what Mobil said in their ads a few years back, and what they told a co-worker when he was considering what oil to put in his new truck. Mobil1.com faq says "change your oil at regular intervals, especially during the warranty period" & "see your owners manual", like you say. So, perhaps they've gone "conventional" on us.

It's so much easier to go with the flow, rather than try to disprove people's rhetorical "data" (LPG engines run cooler, so don't tend to break down an oil as much, which tends to support my position rather than yours). I'm basing my information and decisions on industry-standard testing, oil analysis, and millions of accumulated miles by fellow AMSOIL users following the recommendations above. Without a failure.

If you want to go on believing oil gets dirty from combustion, go ahead. The arguments above are the same things I heard 18 years ago. I prefer to spend my money where it counts.


Oh, that faq I referenced above says you don't have to break in a vehicle with petroleum oil before changing to Mobil 1. So, who you gonna believe?

 

How much is mobil 1 in comparison to a standard 10w30?

 

Roughly twice as much.

------------------
1985 Camaro SC - 2.8L, auto.

http://www.xenodrgn.f2s.com/Frontright.jpg

 

Well, first of all, I would not call my angle on this issue 'going with the flow'. I have found that most people don't think that the contamination issue is the main reason for oil change intervals. Most people (especially AMSOIL people for some reason ) agree with what you say. Don't get me wrong - I think AMSOIL is a high quality product - I just choose not to use it based on my personal preference.

I will keep believing what I said above because it is easily proven and is the truth. It is what my training, my experience, and what all of the other mechanics I have worked with have told me.What part of my diesel engine example did you not understand??

The only thing saving your engines when you run them that long with the same oil, is the extra durability of the synthetic oil. If you were to use synthetic oil AND change it at the normal intervals you would most assuredly extend the life of the engine - even past the current lifespan that you are experiencing with your current habits.

Matt

GM Certified Tech
ASEP Graduate

------------------
1987 GTA L98 MD8 GH3
355 '97 Vortec 4-bolt block, TRW(suck) forged pistons 10:1 CR, TFS 23*, LT4 Hot Cam, Ported plenum and intake, SLP Siam Runners, Edelbrock TES, gutted Cat, Flowmaster, K+N cone, AFPR, TB bypass, AirFoil, !AIR, !A/C, !EVAP, ARAP, 2300 stall, Hotchkis STB.

 

Mobil 1 synthetic, if you have new valve seals, if not, just use the regular oil. If you use synthetic, it'll go straight down the seals and you'll loose most of it before 3000 miles/

------------------
1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission
Borg Warner 7.75" 9 Bolt Rear End with 2.77:1 Gears.

Current Mods: LT4 HOT Cam, Comp Cams 1.52:1 Roller Rocker Arms, Edelbrock TES 1 5/8" Headers, Catco 3" High-Flow Catalytic Converter, Hooker 3" Aerochamber Cat-Back System, Transgo Shift Kit, Performance Resource Chip, Accel Ignition, K&N Filters, JET TPI Air Foil, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET: 14.32 @ 97.7mph
(corrected for elevation)

 

Some of us are old enough to remember bias ply tires, which would last about 10,000 miles if treated right. Radial tires are more durable, but since tires only used to last 10,000 miles, I'd better change my radials every 10,000 miles, just to be sure.

Yep, that sure makes sense.

The reason AMSOIL people typically say what I'm saying, Matt, is because the full AMSOIL-recommended system (oil, air filter and oil filter) also improves filtration. Keep it cleaner, remove the contamination that does occur, and your more durable lube will do just as good a job as it would if it was changed more often. Does that make sense?

Dan, synthetic oil won't go past valve seals any faster than petroleum-based oil (unless a varnish buildup was keeping the oil in with petroleum lube, and synthetic will tend to desolve old petroleum deposits). But, what you have to add to make up for usage will cost you more. For the price of a few quarts of synthetic, assuming you have an air compressor and a valve spring compressor for on-head work or know someone who does, you can change your valve guide seals and be done with it.

New seals will last longer with synthetic (typically - can't speak for every Tom, **** & Harry synthetic out there) than with petroleum-based oils.

[This message has been edited by five7kid (edited July 07, 2001).]

 

I was quite young, but I seem to remember Mobil 1 bottles in the garage that said right of the front "25,000 miles". A few years ago, before their formula change, I called their number on the bottle and asked about whatever happened to the 25,000 mile claim. The guy acted somewhat dumb about it, I guess we are not supposed to remember old marketing ploys. He did end up saying that you can double the mileage of your vehicles recommend change interval. My guess is, if it was good enough to claim 25,000 at one time then is still should be good enough now (maybe even better since the reformulation). They probably don't make that claim anymore because it is not a good way to sell lots of oil if people leave it in the pan for 25,000 miles.

 

as a service advisor i can tell you AMSOIL is the absolute best. there are only 3 companies in the USA that make synthetic. AMSOIL makes it aand does not sell the base stock like the other 2 companies do. i have had cars come in with 200000 and 300000 miles on them and all they used was AMSOIL and changed per instructions which by the way is 15000 miles between changes. in fact i even had one car come in with 500,000 miles and engine/tranny were untouched...what does this tell you......and no, i don't sell the product either

 

changing oil every 3000 miles is a waste of time and money! Use synthetic oil and change it every 10000 miles or every year whichever comes first and you will be safe. How dirty it looks doesn't tell you if it cools,cleans,and lubricates properly. The only way to be sure would be to constantly test oil samples. the air force does that with jet engines. they use synthetic oil and do not change it except when the oil sample calls for it or upon rebuilding the engine.

 

Ya, but we all know the USAF uses that $1600.00 a qt. oil, and a $900.00 oil filter wrench, or was that the Army?

 

I'll still change my Mobil 1 every 3000, I don't care if they say its good for 100,000 miles....

My bike gets Mobil 1 every 2000 miles. (once a year)

------------------
ASE Mechanic/Machinist/Smog Tech

1999 NBM Trans Am
1986 Chevy 3/4 ton pick up
1981 corvette
1995 Kawi ZX6R
and 2 POS commuters...

R.I.P. #3
"He can see air"

[This message has been edited by Engineboy (edited July 07, 2001).]

 

Will you send it to me when you are done with it?

 

For those interested quite some time ago I came across 3 extensive studies on:

Motor Oil
Oil Filters
Oil Additives

http://www.gmtips.com/3rd-degree/

Enter site.
Choose Tips.

Lots of good common sense and technical data including the disecting of oil filters and giving you the truth about them.

Best I can tell staying away from FRAM and going with Mobil 1 and a Mobil 1 filter is about the safest bet. Make up your own mind.

 

You pay shipping... (Haz mat)



------------------
ASE Mechanic/Machinist/Smog Tech

1999 NBM Trans Am
1986 Chevy 3/4 ton pick up
1981 corvette
1995 Kawi ZX6R
and 2 POS commuters...

R.I.P. #3
"He can see air"

 

I currently use valvoline 5w30 regular oil in my IROC. It gets changes EVERY 2000 miles. It currently has 241000 miles on it. Orginal engine, 305 TPI. I NEVER had to go any deeper that replace the valve cover gaskets. Although it does smoke at start up (valve seals). On my new motor (350) in my sig. it will see conventional oil for break in then switch to syn. My opnion on oil change intervil is that oil is cheap compared to replacing an engine!

------------------
89 Iroc 350 TPI,
Forged pistions
Comp roller Cam .510 lift 230dur
Flowmaster exhaust
Dart Iron Eagle heads 200cc runners 64cc chambers
MINI RAM SOON!!!!!
stock TPI for now 24# inj
87 Trans Am GTA 350 TPI
had engine fire hope to get running soon
Flowmaster exhaust

 

group,
I feel that the arguement that it is "a waste" to change oil every 3000 miles is rather unfounded. I can't see how it COULD be a waste to change your oil that often, regardless of who makes the oil.

Now granted I can't find AMSOIL here, so I haven't been able to do my own tests on it. However there is a Royal Purple dist. cent/factory in Humble.. about an hour away.. The most expensive oil they have is $12/qt(mail order, $9.35 if you pick it up.) Assuming 8.25% tax, and a $10 filter.. that's only ~$76 for a standard capacity small block. Unless you drive 3000 miles a week, I don't see that amounting to a waste.

I haven't seen significant enough results using synthetics to say for normal use they are markedly better than a top quality petroleum oil(Castrol, Valvoline.) I have torn down motors that have used "nothing but" one or the other. When changed frequently, and if the motor is kept in proper tune, both types of oil can keep a motor within production tolerances. the bearings tend to look a little more "out of the box" new w/ synthetic, but still perfectly fine with dino oil.

I currently use Castrol GTX 10W30 and an A/C Delco PF1218 oil filter.. every 2500 miles or so.. 3000 is my LIMIT.. and unlike the Speed Limit.. I NEVER exceed it.

Also, for the record Mobil developed the first "economical" synthetic polymer base. I only know this b/c my father worked on the plant design. Synthetic oils have been around since the 30's, but weren't even close to affordable enough for civilians until the late 70's.

I'm not defending, or knocking any brand or type of oil.. just trying to add another perspective to the discussion. When I build my new engine for the RS, I'll break her in w/ Castrol 5W30.. and probably run Mobil 1 or Royal Purple for the rest of it's life.

Anthony

------------------
previous ride: 87 Camaro LT
350, A4.Comp Cams 268H, Edelbrock Preformer intake, Hedman Headers and y-pipe, gutted cat, No AIR/smog pump. 14x3" Open element K&N, Q-jet w/ D hanger and DA rods, adjusted AV spring tension and quick can.

Current ride: 1992 Camaro RS, K&N, Flowmaster, 305, T5, Black, T-tops, 76k miles.

 

Exactly. Most of us agree that being **** about the oil and stretching the life of the oil is not even close to worth it in the long run. Even with the higher cost of synthetics, it is still better to follow the normal oil change intervals and is more cost effective in the long run. If you can't afford to buy oil for your engine than you just better not plan on running it hard.

As far as AMSOIL's 'full system' - it is nothing more than a marketing gimick to get you suckered into buying even more of their products. I mean come-on, what the hell do they take us for??? There is absolutely no way that their air and oil filters are going to magically create a cleaner burning engine, thus......(see above comments).

As far as the USAF using their oil forever.... Who cares. It's the Air Force.. (Go Army). BTW, the Army uses the same practice of testing the oil to see how the engine is running and whether or not it needs work, but they also keep track of mileage and hours (if applicable) on every engine and schedule them for regular oil changes. The oil analysis (AOAP sampling) is only a precautionary procedure to identify engines that are in need of major work before they end up on the side of the road.

Matt

GM Certified Tech.
ASEP Graduate

------------------
1987 GTA L98 MD8 GH3
355 '97 Vortec 4-bolt block, TRW(suck) forged pistons 10:1 CR, TFS 23*, LT4 Hot Cam, Ported plenum and intake, SLP Siam Runners, Edelbrock TES, gutted Cat, Flowmaster, K+N cone, AFPR, TB bypass, AirFoil, !AIR, !A/C, !EVAP, ARAP, 2300 stall, Hotchkis STB.

 

Think about what you're saying. AMSOIL suggests you spend ~$76/year for oil & filters. The (life-time warranty) air filter is cleaned annually with soap and water and re-oiled, not replaced. The oil filter is replaced at the oil change and at six months (or half of the oil mileage). Those who follow their recommendations have engines that don't wear out. Where's the "marketing gimick to get you suckered into buying even more of their products"?

You, who maintains vehicles for those who don't want to do it for themselves and fixes stuff that wears out for a living, want us to believe that we should spend (if we're using the really good stuff as Ragin' suggests) $76/3000 miles (plus labor) "just to be safe" (or ****, using your words).

Who's suckering who?


All this because some poor guy asked an innocent question about synthetic oil, Fram filters, and Slick 50. Sorry, Storm, you didn't deserve this.

 

Actually, not that it matters much, I quit being a mechanic (great experience - bad career outlook) and went back to school and am now an Engineer.

Anywaysss..... 'those who follow their recommendations have engines that don't wear out' - As if AMSOIL users that use their 'system' are the only ones on the planet that are able to make an engine last. My point is that you most assuredly do not need their 'system' to get an engine to last - that is the gimick. Hard to spot when they got you isn't it?

Hey man, it is your engine. If you truly believe that AMSOIL in fact has completely overcome the laws of physics and principles of chemistry, than I guess you had better use it and follow their directions to a T. That must be some phenomenal, pretty much unbelievable $hit. Why not buy some of their stock as well?

As for me, I know better.

Who's suckering who? Well I'm the certified mechanic offering free, quality, experienced advice and telling you what I personally (along with ALL of my mechanic friends) follow...... you are ??????????????????
AN AMSOIL ADVERTISEMENT..............

 

Ok, i stopped reading about 5 replies up. But this regarding how often to change ur oil and weather or not to use synthetic or regular.. Ok,

Everything i have been taught and read, was that synthetic oils are best for engines that are highway driven, THAT is where the long life comes in, that is when u should wait 7000 miles before changing, city driving takes ALOT MORE out of ur engine then highway, so if ur in the city, then ur engine won't always be hot, and therefor the oil wont last as long, so in the city, a regular wale oil or blend will be ok. but no matter wut u have you need to replace it every 3000 - 4000 miles in the city. I use Mobil 1 synthetic because personaly i believe it will protect my engine better and give me better performance. I don't see how an oil can protect for 25,000 miles. I did used to have a chrylser that regular valvoline 10w-40 that was changed about ever 6-7k miles. I took apart the engine recently, 150,000 miles, IT WAS BAD. scared bearings and crap, burnt oil stuff was built up everywhere, the cam was shot. And on the other hand, My 88 GTA has 206,000 miles on it, i run Mobil 1 10-30 synthetic, runs perfect, doesn't leak a drop. No knocks or anything. Now im not trying to tell anyone what to use\do. Just my .02



------------------
88' GTA 350 MODS---> air foil, K&N, Shift Kit, 180* therm, TB bypass

 

lot of good info here and some interesting opinions... I will add my $.02 here...
first of all the reason that some of the synthetic companies say to follow the manufactures recommendation is because they state the recommended intervals that must be met or the warranty will be void... another thing I would like to mention is that on a modified engine with forged pistons will have different expansion rates than an oem engines cast or hyperutectic (spelling?) pistons... in that respect it is to know your engine that will tell you at what intervals to change it based on parts and the habits of the operator...

as far as synthetics, I would not switch to a synthetic on a car that has more that say 45k or is showing sign of seapage... synthetic tend to pick up debris that may be holding the leek at bay and turn the seap into a problem... the best way to look at a synthetic is in a performance manner rather than how long you can go between changes... it does flow faster on cold starts, reducing engine wear and reduces friction due to the flow characteristics and can potentially produce more power...

looking at additives if they are used in an ideal manner some of them are ok or can be benifcial... at the same time some of them have detrimental qualities that are overlooked (such as chlorinated floralcarbons <- corrosive stuff)... my personal opinion, not for me...

zroc