super83Z

IS it true that you can not switch back to regular motor oil once you put synthetic in? Do I have to go through some weird after like 100 miles drain out the synthetic and add more. And do that like 5 times? Or is it ok at next oil change just add synthetic instead of dino oil?

------------------
I WOULD RATHER PUSH A CAMARO THAN DRIVE AN IMPORT

1983Z28 350w/ edelbrock performer RPM power package , dynomax shorty headers, 700R-4 with shift kit, 750cfm carb, edelbrock 3" exhaust system, 16" IROC rims and ASCD SS hood.

future mods:
completely done over suspension, black paint with flames,
T-56 almost ready to go in, TPI swap coming up

Wifes new car:

95Z28, AT, leather, T-tops bone stock for now.

future mods:
header to tailpipe replacement and a cold air intake. Then I am just going to leave it alone

Mark A Shields

I thought didn't have to drain it out once you put it in except after 3,000 miles. I believe Vader said in a couple posts ago, "that you shouldn't mix synthetics, if you must it would be better to put in dino oil", but even this isn't the best idea. I think it has something to due with deposits that form in the engine and how the 2 different types of oil don't work good when changed back from synthetic.

------------------
'86 IROC
T-TOPS, TINTED WINDOWS, BRAKE LIGHT BLACKOUTS
GM GOODWRENCH 350
EDELBROCK TES HEADERS
3" Hooker CatBack w/Aero Chamber muffler
EDELBROCK 600CFM CARB.
KN AIRFILTER
ACCEL HEI DISTRIBUTOR
160* Stat
3:73 Posi
Rebuilt 700R4
B&M Megashifter, 5" Autometer Tach w/shift lite

super83Z

I really don't plan on switching back but is it going to harm anyhting to switch to synthetic? Can I just at the next oil change just put in synthetic instead of regular? Or should I start with a synthetic blend then at the next oil change put in synthetic? Also what wiehgt oil should I run? Is thicker the better?

------------------
I WOULD RATHER PUSH A CAMARO THAN DRIVE AN IMPORT

1983Z28 350w/ edelbrock performer RPM power package , dynomax shorty headers, 700R-4 with shift kit, 750cfm carb, edelbrock 3" exhaust system, 16" IROC rims and ASCD SS hood.

future mods:
completely done over suspension, black paint with flames,
T-56 almost ready to go in, TPI swap coming up

Wifes new car:

95Z28, AT, leather, T-tops bone stock for now.

future mods:
header to tailpipe replacement and a cold air intake. Then I am just going to leave it alone

Mark A Shields

Vader said don't use 5w-30 because if you understand synthetics, I guess he's saying they are already thin and lubricate and 5w-30 would be too light. I just use Mobil 1 10w-30. When I first got my new motor I put in dino, and ran drove it for 500 miles and changed the oil with more dino. After about 3k miles I drained the dino and switched to Mobil 1.

------------------
'86 IROC
T-TOPS, TINTED WINDOWS, BRAKE LIGHT BLACKOUTS
GM GOODWRENCH 350
EDELBROCK TES HEADERS
3" Hooker CatBack w/Aero Chamber muffler
EDELBROCK 600CFM CARB.
KN AIRFILTER
ACCEL HEI DISTRIBUTOR
160* Stat
3:73 Posi
Rebuilt 700R4
B&M Megashifter, 5" Autometer Tach w/shift lite

RB83L69

None of that kind of foolishness is necessary. Just change over and be done with it.

As far as the viscosity, synthetic is much more stable than dinosaur juice, so it's not nearly as much of an issue. In general, synth is thinner than dino juice at low temps and thicker at high temps anyway.

Personally I prefer to run the thinnest synthetic I can find. I use Mobil 1 5W-30 or even 0W-30. It's about the same viscosity as straight 30 fossil oil at engine operating temp. But I think the difference in lubricating properties between synthetic and fossil oils is so much greater than any difference between oil weights that it hardly matters. If your motor is older, just run the most common synthetic weight which is 10W-30 and be done with it.

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

super83Z

Pleae don't mind my questions. I have about 3K miles on the rebuild right now so it is not an old motor. So what are the thicker oils for like 20W-50? Since the number before the W is the weight what does the second number stand for? If it stands for Viscosity then what is viscosity? thanks for clearing this up guys.

------------------
I WOULD RATHER PUSH A CAMARO THAN DRIVE AN IMPORT

1983Z28 350w/ edelbrock performer RPM power package , dynomax shorty headers, 700R-4 with shift kit, 750cfm carb, edelbrock 3" exhaust system, 16" IROC rims and ASCD SS hood.

future mods:
completely done over suspension, black paint with flames,
T-56 almost ready to go in, TPI swap coming up

Wifes new car:

95Z28, AT, leather, T-tops bone stock for now.

future mods:
header to tailpipe replacement and a cold air intake. Then I am just going to leave it alone

TransamGTA350

iTrader: (2)

W does not stand for weight. It means that the viscocity was rated at 0 degrees F. Without the W means the viscocity was rated at 210 degrees F.

5W-30
Viscosity of 5 at 0 degrees F.
Viscocity of 30 at 210 degrees F.

------------------
89 Transam GTA, 350TPI, auto, 3.27 rear, dual cats, gray.
Magnaflow cat-back,
K&N open element,
Best E.T. 14.63@95mph

super83Z

oh ok. is it logical to run like 20W-50 then? Or is it too thick? and why?

------------------
I WOULD RATHER PUSH A CAMARO THAN DRIVE AN IMPORT

1983Z28 350w/ edelbrock performer RPM power package , dynomax shorty headers, 700R-4 with shift kit, 750cfm carb, edelbrock 3" exhaust system, 16" IROC rims and ASCD SS hood.

future mods:
completely done over suspension, black paint with flames,
T-56 almost ready to go in, TPI swap coming up

Wifes new car:

95Z28, AT, leather, T-tops bone stock for now.

future mods:
header to tailpipe replacement and a cold air intake. Then I am just going to leave it alone

SSC

You could run it with no problems if you could find it.
Most people run 10-30 because its common and its whats stamped on the oil cap of our engines.
Since you have 3000 miles on your engine just stick with 10-30 mobil1 and change it regularly, every 3k for a while and you will be fine.
SSC

five7kid

iTrader: (14)

20W50 was originally intended for loosely assembled race engines that ran hot. It was more of an issue before synthetics became readily available.

As for switching over to synthetics, the issue is two-fold: 1) for high mileage engines, the petroleum-based oil most likely left a bunch of varnish and sludge in the engine, which the high detergent-property synthetic will desolve quickly resulting in contamination of the synthetic. 2) For newly rebuilt engines, you want a little wear to occur between the cylinder walls and rings to "seat" the rings and provide a better seal. Since synthetics tend to reduce wear, it can take longer to seat the rings if you fire it up with synthetic. However, 3000 miles is more than enough to have achieved that, so the switch to synthetic can be accomplished with no concerns. 10W30 is a good overall choice, although I've been using 0W30 in all my vehicles for about 4 years now.

There is no problem going from synthetic to petroleum-based oil, other than you're going to an inferior product.

------------------
82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. 2-1/2" cat-back, ZZ3 intake, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 CC system w/'87 LB9 block, ZZ3 cam, ported World 305 heads, Hooker 2055 headers, 3" Catco cat & 3" catback, restalled TC, Spohn SFCs).
57 Bel Air, my 1st car. '66 396, 9.7 CR forged TRWs, Weiand Action+, Holley 750VS w/4150 conversion, 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).

Vader

83Z,

It is O.K. to just switch to synthetic with no special preparation. You can always change back to mineral oil, or even add mineral oil without any problems.

The thing I caution against is mixing two types of synthetics. If you are positive that the two synthetics are of the same base, then you can mix. If you aren't sure of the base formulation, add mineral oil instead. Adding a polyol ester based syn to a synthesized hydrocarbon, like polyalphaolefin, can cause precipitation of long chain molecules and a near complete loss of lubrication properties of the fluid. You'd be shopping for a new crank in a matter of miles.

I use Mobil 1 because it has more years of development and engineering behind it, is available in almost any location, and is formulated to cover all my needs. I know that Amsoil is a very good and compatible synthetic, and there are probably others as well. What scares the hell out of me are these "synthetic blends". Since the base stock is mineral oil and can probably provide most of the lubrication, the blenders can add nearly any synthetic additives of any variety to enhance the oil however they desire. Many of these are probably not compatible with dialkylated benzenes, POE, or PAO based synthetic lubricants, and could wreak havoc if used to top off a synthetic sump.

If you are going to commit to syn, go all the way or don't do it at all.

------------------
Later,
Vader
------------------
Justice and Freedom will Prevail

Bugsbunny

Vader,

Here's my situation: I have 120,000 miles using regular oil. Now I'm planning on switching to synthetic mobile 1. I also want to start using Prolong. Is it ok for me to change over and use both of these together?

Thanks,

Bugsbunny

RB83L69

I'm not Vader... but IMHO, you should change to Mobil 1 ASAP and skip the Prolong.

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

Bugsbunny

I think your right. I just finally stumbled upon a post by vader saying he using just synthetic and looked into his motor after about 100+K miles and it was still like new. I've read many posts before but I wanted to question it because some people/friends swear up and down that it increases mileage and their cars run smoother. I really don't know if it works or not but there seems to be a general consensus that using mobil 1 alone and changing every 3k is as good as anyone could ask for. So I'll just do that and try to figure out something to do with the $20 Prolong I already bought a couple months ago.

Thanks,

Bugs

NTChrist

So, if viscosity is the amount that a liquid will resist flowing, why doesn't oil have a lower viscosity rating for higher temperatures? Or, put differently, why is the second number always higher? As motor oil (regardless of additive package) heats up, it thins, right?

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

PonyKillerZ

VADER


So when I switch to 5-w30...after runnin 10-w30...I could have a problem?

rezinn

If you have decent oil pressure with 5w30, there shouldn't be any problems.

Oh, and 5w30 is stamped on the oil cap of my engine. I've been using mobil1 15w50 for a while with no trouble. The engine was run with havoline 10w30 for ten thousand miles.

[This message has been edited by rezinn (edited September 27, 2001).]

Sitting Bull

Actually, in Canada we used 20/50 for propane engines because of the apparent high heat protection advantages. Eventually everyone just ran ordinary 10/30 and noticed no difference :/


------------------
1986 Camaro Sports Coupe
T-tops, variable wiper, power hatch, rear defrost, third brake light
LG4 305 V8, Hooker Shorty headers, 3" pipe into Walker Quiet Flow dual exhaust
Edelbrock Performer intake, "Damonized" Q-Jet 4bbl, K&N filter, Crane ignition kit
TH700R4 transmission and Derale cooler
Air conditioning, power windows, power door locks, power brakes, power steering, tilt wheel
Kenwood cassette, Pioneer 6x4 component front speakers
Rockford Fosgate 6x9 Punch rear speakers
Z-28 front and rear sway bars
Aluminum slots and Goodyear 225x60R15 Eagle HP tires
243 horsepower and 326 foot pounds of torque at the flywheel
_ _ _ _ _ __ _ _ _ _ _
Yea verily, and he smote the smog heathens from his small block Chevy, even from the air pump to the converter ...
Todd 1:1

super83Z

thanks for all the help in clearing that up guys. Thanks for learning me!

------------------
I WOULD RATHER PUSH A CAMARO THAN DRIVE AN IMPORT

1983Z28 350w/ edelbrock performer RPM power package , dynomax shorty headers, 700R-4 with shift kit, 750cfm carb, edelbrock 3" exhaust system, 16" IROC rims and ASCD SS hood.

future mods:
completely done over suspension, black paint with flames,
T-56 almost ready to go in, TPI swap coming up

Wifes new car:

95Z28, AT, leather, T-tops bone stock for now.

future mods:
header to tailpipe replacement and a cold air intake. Then I am just going to leave it alone

Vader

Actually, it was an LT1 that had lived on synthetic lube since day one. It had 109K miles on it when it came out for a new cam, head work, and a few other freshenings. It isn't easy to see in the photo, but the ridge in the bore was basically only carbon where the rings didn't scrape the walls.



Without getting into all the numbers and details, the engine didn't look new, it measured new. It was still within production tolerances, and hadn't even come close to starting into the wear tolerances. If it hadn't been for the carbon and a little polishing of the piston skirts, I would have thought the engine hadn't even been broken in. The car was never babied, either, since it was on its third set of rear tires and needing a fourth. The digital speedo had been in the "14X" range more than once and for several miles. Come to think of it, that "1" showed up in the display more than I can remember.

As for the Prolong (or any other additive), I wouldn't even park in the same lot with that stuff. But I'm only basing that decision on my experience. I've never driven a Viper with no oil around a closed course for twenty minutes then torn it down to check wear. Briggs & Stratton, however, did perform their own little "oil vs. no-oil" test and ended up suing Prolong for using their name in advertisements. Briggs discovered that there was actually less damage to the engines when oil was drained with no Prolong being applied. Engines filled with Prolong, then drained and run with nothing in the sump actually suffered more damage than their other test engines that had only oil drained. Is that a hint?

------------------
Later,
Vader
------------------
Justice and Freedom will Prevail

Vader

Rezinn,

Absolutely right. If you hold good oil pressure at operating temperatures with 5W30, then go for it. It is possible to have too much oil pressure to the point of snapping the oil pump drive or bursting a filter. High RPM engines really need to have control over oil pressure to prevent excessive pressure and all its problems. All that oil pumping uses energy, too, so in a performance engine or even for maximum efficiency, thinner oil can help. For a street engine that rarely reaches high RPMs, however, a little extra oil pressure is cheap insurance.

Read the filler cap, then the owner's manual. You'll see that the manual actually recommends a higher viscosity above 40°F ambients. Manufacturers have pushed the 5W30 and sized oil pumps in their engines to provide minimum safe (but still adequate) oil pressures and the maximum fleet fuel economy to satisfy federal fleet milage rquirements. Since I try not to drive a "sheep-mobile", I don't mind having a little more oil pressure to go with the extra power.

------------------
Later,
Vader
------------------
Justice and Freedom will Prevail

RB83L69

Sheep-mobile

ROTFLMFAO!!!!

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

DM91RS

I have a question on the high detergent properties of syn such as Mobil 1. Could this oil be used to clean an engine with over 100k miles and then return to regular oil without any problems?

Vader

DM,

You should be able to switch to synthetic, then back to mineral oil if you wish. There are no detrimental mechanical effects of the oil change. However, as several people have experienced, if you have crankcase seals or gaskets that have hardened or failed, you may now have a layer of external sludge and varnish that is effectively sealing the leakage. The solvent properties of synthetic will tend to clean up and loosen that sludge and varnish, which can make the leakage more apparent.

Synthetics don't damage seals and gaskets, but will clean up any oil leakage area to make it leak more. If your case seals are in good condition, you don't have anything to fear. If they are already leaking, they needed repair anyway. At 100K miles, your seals may still be in good condition.

------------------
Later,
Vader
------------------
Justice and Freedom will Prevail
Adobe Acrobat Reader

DM91RS

Vader, thanks for the info! My seals all seem fairly good but replacing any would not be a problem as I'm fixing to do a cam change and some other work anyway. But, if I deceided to run syn all the time how often is the recommended change? I change my Castrol at 2000 to 2500 miles.

------------------
91 RS 5.0 TBI....Edel. TES headers .. 3" exhaust ...Dynomax muffler...5spd... 3.08...underdrive pulleys...cold air K&N flat bottom breather...strut tower brace...6-point rollbar...sub-frame connectors...Koni shocks and struts...16" Black GTA wheels...Autometer guages...custom chip...Grant steering wheel...a/c delete...smog delete...rear seat delete...ultimate TBI mods...afpr...36mm front and 25mm rear swaybars with poly bushings...

TransamGTA350

iTrader: (2)

NTChrist,
You are right in your assumption that oil gets thinner as it heats up. SAE 30 is much higer viscosity when at 0 degrees F, but a multi-viscosity oil like 5W-30 is blended so it is actually like 2 different oils. A low viscosity for cold and a high viscosity for hot. A straight grade is actually a more durable oil, but is only good for a limited temperature range. Usually too thick when it's cold and too thin when it's hot.

------------------
89 Transam GTA, 350TPI, auto, 3.27 rear, dual cats, gray.
Magnaflow cat-back,
K&N open element,
Best E.T. 14.63@95mph

super83Z

What about that purple oil?

------------------
I WOULD RATHER PUSH A CAMARO THAN DRIVE AN IMPORT

1983Z28 350w/ edelbrock performer RPM power package , dynomax shorty headers, 700R-4 with shift kit, 750cfm carb, edelbrock 3" exhaust system, 16" IROC rims and ASCD SS hood.

future mods:
completely done over suspension, black paint with flames,
T-56 almost ready to go in, TPI swap coming up

Wifes new car:

95Z28, AT, leather, T-tops bone stock for now.

future mods:
header to tailpipe replacement and a cold air intake. Then I am just going to leave it alone