Black Beauty

what will the result be of me switching from 10-30 synthetic to 20-50 regular? my car has 100,000 miles now and i think the synthetic is too thin and expensive for it. thanks for any help you may provide

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Rick
90 Camaro RS 305 TBI
400 small block, Hooker 1 3/4 LTs, Random Tech Cat, Hooker aero chamber cat back on the way!!
TH700-R4 with Trans-Go shift kit (corvette servo here...but not installed yet)
MacEwen Motorsports White Gauge Overlays
14" K&N X-Stream Open Element
GTS Headlight and Taillight covers
5% Limo Tint all around
Classic White Chevy Bowtie sticker on rear window
http://www.geocities.com/esvalenz

Man if my camaro were a rice-rocket all those mods would give me what...easily 50-60 hp!!!

"Just because I've done it, doesn't mean I knew what I was doing!" - Me

jcb999

I would not use 20-50 for anything. Find a 15-40 or something like that. Even in LA 20 is too thick at startup. You won't make it 120K miles hammering on the bottom end with 20 weight at startup.

I ROCK

I use Mobil 1 15w50 in the thirdgen and castrol gtx 15w50 conventional in my beater. I've never had a problem with cold weather and switching from 5w-30 to 15w50 synthetic really bumped up my oil pressure.

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89 Iroc-Z LB9 305 TPI auto 2.73 posi:
3" Dynomax "cat" back,K&N filters, TB bypass, 3" pipe in place of cat, cleaned and flow-matched injectors, 180' thermo, mild ignition mods, synthetic oil, kicker sound system, soon to attempt engine swap...

five7kid

iTrader: (14)

The result is that you will no longer enjoy the benefits of a synthetic lubricant; fuel consumption will go up, and your engine will wear out sooner.

What does "too thin" have to do with 100k miles? That "thin" Mobil 1 10W30 will protect your engine better that a "thick" 20W50 petroleum-based oil.

If you aren't having any consumption or leakage problems, stick with the synthetic. Your engine has fewer miles on it than mine did when I SWITCHED to synthetic! With 137k miles currently, I'm using AMSOIL 10W30 with no leakage or consumption problems. If you think it's too expensive, you're probably doing that "old school" thing of changing the oil every 3000 miles - required for petroleum-based lubes, but a real waste to change a quality synthetic (like AMSOIL or Mobil 1) that often.


P.S.: Mobil 1 will protect your engine better with 10k miles on the oil than fresh 20W50 petroleum oil will. I'm even more confident making that statement with AMSOIL.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R. 2.73 unlimited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LB9 w/ZZ3 cam, TBD heads, exhaust, paint, etc.).
57 Bel Air, my 1st car. 0.030 over 396, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

KS91Z28

This may be a dumb question, but how often are you supposed to change your oil if you are using synthetic oil?

five7kid

iTrader: (14)

AMSOIL's recommendation is 25k or one year with their "standard" synthetic, and 35k or one year for their Series 2000 synthetic, with a filter change at half that interval (when using their filters). Mobil 1 recommends following the factory change interval during the warranty period, then 25k or one year after that.

five7kid

iTrader: (14)

Should add that AMSOIL's recommendations are for what they call a "mechanically-sound engine".

And, I've been following AMSOIL's change intervals for almost 18 years. I haven't worn out an engine yet.

theformula

Use either 5w30 or 10w30

All I'm going to say

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91 Formula
305 TPI 5speed
1LE/G92/WS6
K&N, SLP airfoil, ported/polished plenum, March pulleys, TB coolant bypass,Crane AFPR(47psi),Crane Gold 1.6rrs,MSD coil,MSD6AL, Holley 9mm wires,Bosch O2sensor, SLP headers & catback,3:73s w/Auburn posi,160* t-stat,JET 195* fan switch, Macewen white face gauges, Autometer gauges, Zoom hi-performance clutch.
Street legal with stock throttle body, runners,intake manifold,cam, and heads.

[This message has been edited by theformula (edited January 10, 2001).]

David M

KS91Z good question. I'm using Mobil 1 synthetic 10W30 in my daily driver ('98 S10 4.3 V6) I'm changing the oil & filter every 7K mi. Too frequent?

stingerssx

10w-40 Nothing more, nothing less.

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'82 Firebird, dead stock, 9 bolt disc rear, over 200,000 miles and still going strong, more to come...
http://www.spinfrenzy.com/stingerssx...easures.html#4

KS91Z28

Ok, so if I'm using Mobil 1 10w30 and they recommend to change the oil every 25k or once a year, how often should I change the filter?

David M

KS91, I have heard every 5K mi. and replace the quart you lost.

five7kid

iTrader: (14)

David, that's a reasonable interval (although I haven't seen anything "official" from Mobil).

Stinger, 10W40 is not a good weight to use because of the extra VI improvers that have to be added, which are the first thing to break down in an oil. Roller lifters especially do not like it when that happens. The sliding action of a flat tappet cam is about the hardest thing on those additives, so you're not much better off there.

camaro6spd

THAT IS TOTAL BS!!!!
You still have dirt comeing in from the outside, and combustion by products.....You can change you oil every 25K but once you reach 28K your mtor will blow....I saw this happen, I lady I knew put Moble1 in and never chagne the oil after that, along witha Moble1 filter.....anyway at 28,000 miles the engine failed......

five7kid

iTrader: (14)

Sir, you are way out of line. I know of what I speak. Having one example does not tell the whole story. There's probably more to that lady's story that you either don't know or aren't including.

If you will notice, I said in this (and the other post you dug up) that filtration is a very important factor. But, the "dirt" that contaminates a petroleum-based oil comes primarily from the oil itself: breakdown of the base lubricant and the additives used to "fortify" it. Combustion by-products are a very small portion of that "dirt" in a sound engine.

I'd go on, but I'm not sure your mind is open enough to recieve any real information.