Oil spec
Thread Starter
3rd Gear
Joined: May 2010
Posts: 3
Likes: 0
From: South Carolina
Oil spec
Just had oil changed on 95 LT1 at dealer and noticed that cost was low -- turns out they used synthetic blend rather than full synthetic. I called and was informed that this is new spec. Is this correct or should I go back and insist on full synthetic?
Burning Brakes
Joined: Feb 2009
Posts: 785
Likes: 3
From: Richmond Virginia
I'd take it back and get full synthetic, yours calls for full synthetic-should be on the OE oil cap (Mobil 1)
IMO that "new spec" sounds like a load of crap-someones just trying to cover their ****
IMO that "new spec" sounds like a load of crap-someones just trying to cover their ****
Le Mans Master
Joined: Jun 2009
Posts: 6,528
Likes: 752
From: South Dakota
I have never seen a synthetic blend that meets the GM4718M oil requirement for our cars. Some full synthetics do not meet this spec.
I would be very surprised if the dealer has a synthetic blend that meets it.
I agree it sounds like the dealer made a mistake and is trying to cover it up.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
The oil "spec" for LT1 motors is a full synthetic that meets the GM4718M standard. The dealer can't change that.
That's one reason why some dealers have such a bad reputation. And expect to pay much more for a full synthetic oil like Mobil-1 at a dealer. Figure $12 to $15 per quart. If you want the dealer to continue to do the work for you, bring your own oil. $25 for a 5-quart jug of Mobil-1 5W30 at Walmart. 1 extra quart at most parts stores $7.
That's one reason why some dealers have such a bad reputation. And expect to pay much more for a full synthetic oil like Mobil-1 at a dealer. Figure $12 to $15 per quart. If you want the dealer to continue to do the work for you, bring your own oil. $25 for a 5-quart jug of Mobil-1 5W30 at Walmart. 1 extra quart at most parts stores $7.
Drifting
Joined: Dec 2007
Posts: 1,647
Likes: 4
From: Argillite KY
The only NEW spec that I'm aware of is the GM switch to DEXOS1 in 2011 model year vehicles. It is also backward compatible to replace all earlier synthetics. I would assume that would include Mobil 1 used in our engines. It is a full synthetic I believe. There are other full synthetics that meet these specs and are available at most auto parts stores. Just search for DEXOS1 compatibility. --Good Luck--
Le Mans Master
Joined: Jun 2006
Posts: 5,642
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From: One day you're a Comet...the next day you're dust... Arkansas
Synthetic blends are only 5%-10% synthetic. I use them in my L98 where the spec is for Dino anyway. That is not what was intended for the LT cars. However, you will never tell the difference.
Team Owner
Joined: Sep 2003
Posts: 20,179
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From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
How about you go into any auto parts store and compare part vs full syn prices.
If you asked for full syn then you should have full syn.
If you asked for full syn then you should have full syn.
