Rebuilt MerCruiser 4.3 on the way.
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that Chevy V-6 is just a 350 Chevy with 2 cylinders lopped off.
Rotella 5W-40 would be a good choice.
Rotella 5W-40 would be a good choice.
I agree with the Rotella 5W40. Non synthetic. Gas engine rated.
I've got the same motor, it gets Mobil 1 Euro 0w40
Merc 25/40
I just don't understand.
I would use a FC-W rated oil myself. A semi-synthetic, like Ecstar v7000.
Engine Oil
For optimum engine performance and maximum protection, use the following oil:
Application Recommended Oil
All MerCruiser engines Mercury MerCruiser Full-Synthetic Engine Oil, 20W-40, NMMC FC-W rated
IMPORTANT: Lubrication requirements for catalyzed engines differ from the requirements for non-catalyzed engines. Some marine-grade lubricants contain high levels of phosphorus, which can damage the catalyst system on MerCruiser engines. Although these high-phosphorus lubricants may allow acceptable engine performance, exposure over time will damage the catalyst. Catalysts damaged by lubricants containing high levels of phosphorus may not be covered by the MerCruiser Limited Warranty.
If Mercury MerCruiser Full-Synthetic, 20W-40 oils is unavailable, use the following lubricants, listed in order of recommendation. If you are servicing a catalyst engine, use these for short periods of time only.
Mercury/Quicksilver 25W-40 Synthetic Blend, NMMA FC-W-rated 4-cycle MerCruiser oil
Mercury/Quicksilver 25W-40, NMMA FC-W-rated 4-cycle MerCruiser oil
Other recognized brands of NMMA FC-W-rated 4-cycle oils
A good-grade, straight-weight detergent automotive oil according to the last row of the operating chart below.
NOTE: We do not recommend non-detergent oils, multi-viscosity oils (other than as specified), non-FC-W-rated synthetic oils, low-quality oils, or oils that contain solid additives.
This crankcase oil recommendation supersedes all previously printed crankcase oil recommendations for MerCruiser gasoline engines. The reason for this change is to include the newer engine oils that are now available in the recommendation.
For optimum engine performance and maximum protection, use the following oil:
Application Recommended Oil
All MerCruiser engines Mercury MerCruiser Full-Synthetic Engine Oil, 20W-40, NMMC FC-W rated
IMPORTANT: Lubrication requirements for catalyzed engines differ from the requirements for non-catalyzed engines. Some marine-grade lubricants contain high levels of phosphorus, which can damage the catalyst system on MerCruiser engines. Although these high-phosphorus lubricants may allow acceptable engine performance, exposure over time will damage the catalyst. Catalysts damaged by lubricants containing high levels of phosphorus may not be covered by the MerCruiser Limited Warranty.
If Mercury MerCruiser Full-Synthetic, 20W-40 oils is unavailable, use the following lubricants, listed in order of recommendation. If you are servicing a catalyst engine, use these for short periods of time only.
Mercury/Quicksilver 25W-40 Synthetic Blend, NMMA FC-W-rated 4-cycle MerCruiser oil
Mercury/Quicksilver 25W-40, NMMA FC-W-rated 4-cycle MerCruiser oil
Other recognized brands of NMMA FC-W-rated 4-cycle oils
A good-grade, straight-weight detergent automotive oil according to the last row of the operating chart below.
NOTE: We do not recommend non-detergent oils, multi-viscosity oils (other than as specified), non-FC-W-rated synthetic oils, low-quality oils, or oils that contain solid additives.
This crankcase oil recommendation supersedes all previously printed crankcase oil recommendations for MerCruiser gasoline engines. The reason for this change is to include the newer engine oils that are now available in the recommendation.
+1 (Rotella T6) Used it for 18 years in my 2002 with a 4.3.
One wonders if it even needs a special break-in oil. Most engines do not.
What does Michigan Motorz say?
What does Michigan Motorz say?
When I put a reman engine in my Jeep Grand Cherokee the reman company recommend a non synthetic for the first few oil changes.
The shop owner says he’s going to put Schaffer’s 20w50 synthetic blend high zinc for break in. As far as repair I believe he knows what he’s doing.
This site taught me that mechanics know the least about oil though.
I’m sure the Schaffer’s is fine too. What are y’all’s opinions?
This site taught me that mechanics know the least about oil though.
I’m sure the Schaffer’s is fine too. What are y’all’s opinions?
Why they wouldn't use an oil with a marine license is puzzling, at least to me. That's what matters in this situation. Look at tyman's post above, notice something that is repeated over and over?
I found out Michigan Motorz recommends plain ole Rottella T 15w40. No mention of a Marine specific oil. They recommend waiting 100 hours before synthetic. So that’s what I’ll do. My original plan was to use a syn diesel 15w40 for the life of the boat but as most BITOG extremist I was trying to do a little extra and see if a break in specific oil was a good idea and all the ones I found were 30 weight.
Okay. Why one wouldn't use what the manufacturer states in their manual is still pretty unfathomable to me, especially for an expensive motor like that. But maybe that's just me.
Just make sure the Rotella 15W40 is gas rated. Rotella has formulated some of their heavy duty oils to be diesel only when they use to be gas & diesel.
I am a fan of Rotell 15W40. I used it in my Mercruiser 260 (5.7L).
I am a fan of Rotell 15W40. I used it in my Mercruiser 260 (5.7L).
The FC-W spec is 20 years old. About the same age as API SJ.
I've used Valvoline conventional VR1 20w-50 for the last 2 overhauled auto engine run ins. I also use it in my old Century Resorter w/ the GM 350. Rotella is a great oil and will be fine, and what I would use if MM recommends it.
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