Sae 40

veritas honus

Lieutenant Commander
Joined
Jun 13, 2010
Messages
1,876
My 4.3L Yamaha calls for SAE 40 oil. Does anyone know where I can find it in full synthetic? The only SAE 40 oil I've been able to find is Castrol at Advanced Auto. Everywhere else I've tried has SAE 30. Nothing but "dino" oil. The oil in it right now has about twenty hours on it, and it looks brand new. I don't think I'm "looking for trouble" by switching to synthetic. I'm just looking to use what will perform best. The motor is 19 years old, and it runs like a new motor. It's aways been very well maintained and always will be. All input is welcome. Thanks.

Safe and happy boating always!!!
 

Aloysius

Chief Petty Officer
Joined
Aug 21, 2010
Messages
484
Re: Sae 40

4.3? Chevy v6? It's a car engine..use whatever the other Chevy guys use. Doesn't have to be straight 40 weight.
 

ziggy

Admiral
Joined
Jun 30, 2004
Messages
7,473
Re: Sae 40

how about trying out the yamaha dealer since there the ones that marinized your 4.3 and say it should use straight 40w... if that's what they say...
call them up, maybe they can tell you there's sb out that superceeds your need for straight 40w (if there is one? i don't know, but the question couldn't hurt to ask) too so that you can still use what the oem thinks is best for their engine.
 

ricovw

Petty Officer 2nd Class
Joined
Sep 2, 2009
Messages
167
Re: Sae 40

Yes, it is a chevy 4.3 V6. That is the v6 that yamaha marinized.

I have the yamaha L4, which is the chevy 3.0, and it also calls for sae 40. I also have a hard time finding it. I have used sae 30. i have found the sae 40 sold as heavy duty industrial oil at Canadian Tire, but thats in Canada! If you cant find the 40, just use the 30. That would be fine.
 

Lyle29464

Lieutenant
Joined
Mar 10, 2009
Messages
1,261
Re: Sae 40

4.3? Chevy v6? It's a car engine..use whatever the other Chevy guys use. Doesn't have to be straight 40 weight.

The boat engine needs the 40 weight. A car will do fine with 5w20 etc

You really can't compare them.
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
13,023
Re: Sae 40

Honestly I would not switch a 19 year old motor to synthetic. What really is the point, if what you used worked this well then I'd keep doing whatever you did to make it last this long. For a marine inboard or I/O you can use either a straight weight Chevron Delo 400, Shell Rotella T or Pennzoil Marine in 30 or 40 wt. Another alternative is the Merc 25/40 that is available in a full synthetic. I use Chevron Delo 400...
 

kmarine

Chief Petty Officer
Joined
Nov 5, 2010
Messages
591
Re: Sae 40

I use siearra 25w40 on all the boats I service. It is available in both conventional and synthetic. I usiually do not recomend switching to synthetic on boats with over 100 hours.
 

veritas honus

Lieutenant Commander
Joined
Jun 13, 2010
Messages
1,876
Re: Sae 40

Honestly I would not switch a 19 year old motor to synthetic. What really is the point, if what you used worked this well then I'd keep doing whatever you did to make it last this long. For a marine inboard or I/O you can use either a straight weight Chevron Delo 400, Shell Rotella T or Pennzoil Marine in 30 or 40 wt. Another alternative is the Merc 25/40 that is available in a full synthetic. I use Chevron Delo 400...

Do you know of any national chains or franchise stores that carry the products you've named? All I've been able to find is the Castrol in SAE 40. Don't get me wrong, I have no problem with Castrol. I think I've chosen the very best of all one of my options;). I'm simply looking for more options for possibly better protection. You mentioned Penzoil Marine. Is there any difference between Penzoil Marine SAE 40 and Penzoil SAE 40 other than packaging?

Safe and happy boating always!!!
 

LAC_STS

Master Chief Petty Officer
Joined
Jul 1, 2010
Messages
895
Re: Sae 40

I use straight 30 and it's available everywhere down here. Same brands Lou C said. Wallmart, and all the local autoparts stores. West marine sells penzoil marine for $17. Wallmart sells Rotella for 14.

I agree keep with what has been working so good.
 

veritas honus

Lieutenant Commander
Joined
Jun 13, 2010
Messages
1,876
Re: Sae 40

how about trying out the yamaha dealer since there the ones that marinized your 4.3 and say it should use straight 40w... if that's what they say...
call them up, maybe they can tell you there's sb out that superceeds your need for straight 40w (if there is one? i don't know, but the question couldn't hurt to ask) too so that you can still use what the oem thinks is best for their engine.

The OEM service manual says to use SAE 40. "Use SAE 40" is engraved on the oil dipstick. The motor is nineteen years old. There are no warrenty issues. I'm sure that I can safely use anywhere from 10W30 to 20W50. My preferance is SAE 40. Do you know if it's even available in synthetic?

Safe and happy boating always!!!
 

veritas honus

Lieutenant Commander
Joined
Jun 13, 2010
Messages
1,876
Re: Sae 40

I use siearra 25w40 on all the boats I service. It is available in both conventional and synthetic. I usiually do not recomend switching to synthetic on boats with over 100 hours.

Why do you usually not recomend switching to synthetic on boats with over 100hrs? My motor has no oil leaks. It's my understanding that switching from conventional oil to synthetic will make existing oil leaks worse; but if there are no leaks, then it's not an issue and there's no problem with switching. That's just what I've learned. Any additional education you can give me is very much appreciated.

Safe and happy boating always!!!
 

brhodes

Petty Officer 2nd Class
Joined
Aug 25, 2009
Messages
102
Re: Sae 40

After reading many of the dreaded "oil threads" over the year, I defaulted to the people that built the thing (merc 5.7) and used old school SAE 40, although it was a little harder to find than SAE 30, as in O'Reilly didn't have it, had to go to Autozone. Use whatever you want, but it has been said here many times that boat motors don't fail cause you changed to the wrong oil. I have also found, regarding my car, that I can ask 2 different seasoned, capable mechanics about oil, one says "its all the same, just change it at a reasonable clip", to the other guy telling me to buy synthetic. Pick what you think is best, sleep well knowing you changed it. Just my .02, good luck
 

Aloysius

Chief Petty Officer
Joined
Aug 21, 2010
Messages
484
Re: Sae 40

20 years ago, oils were much different than today. Multi-grade oils were not as durable, the additive package was inferior, and synthetics were in their infancy.

Times change. Products change. "thick" oils have fallen out of favor, and for good reason.
 

Bluestream

Petty Officer 1st Class
Joined
Sep 28, 2010
Messages
296
Re: Sae 40

I use siearra 25w40 on all the boats I service. It is available in both conventional and synthetic. I usiually do not recomend switching to synthetic on boats with over 100 hours.

Why not? That makes no sense..
 

Bluestream

Petty Officer 1st Class
Joined
Sep 28, 2010
Messages
296
Re: Sae 40

Do you know of any national chains or franchise stores that carry the products you've named? All I've been able to find is the Castrol in SAE 40. Don't get me wrong, I have no problem with Castrol. I think I've chosen the very best of all one of my options;). I'm simply looking for more options for possibly better protection. You mentioned Penzoil Marine. Is there any difference between Penzoil Marine SAE 40 and Penzoil SAE 40 other than packaging?

Safe and happy boating always!!!

The old synthetic makes your engine leak myth goes way back to the 70's when seals were made of rubber and not compatible with synthetic oil . Today, you can switch to synthetic at any time and not worry about leaks at all. If you want a SAE40 Amsoil makes one IIRC. Why not stick with a 30 weight? It was all that OMC ever recommend at the engines were the same. Will give you a bit better fuel economy to boot
 

Dakota47

Senior Chief Petty Officer
Joined
May 22, 2007
Messages
722
Re: Sae 40

Shell Rotella T-5 Semi Synthetic 15W40 will work great in that motor, and its on sale for $9.99 for 4 quart jug @ Wal-Mart.
 

sethjon

Senior Chief Petty Officer
Joined
Jun 8, 2010
Messages
692
Re: Sae 40

My 4.3L Yamaha calls for SAE 40 oil. Does anyone know where I can find it in full synthetic? The only SAE 40 oil I've been able to find is Castrol at Advanced Auto. Everywhere else I've tried has SAE 30. Nothing but "dino" oil. The oil in it right now has about twenty hours on it, and it looks brand new. I don't think I'm "looking for trouble" by switching to synthetic. I'm just looking to use what will perform best. The motor is 19 years old, and it runs like a new motor. It's aways been very well maintained and always will be. All input is welcome. Thanks.

Safe and happy boating always!!!

Why switch to synthetic? It doesn't make the engine go faster, get better mileage. or power. In fact I can't think of one really good reason to use it.
 

sethjon

Senior Chief Petty Officer
Joined
Jun 8, 2010
Messages
692
Re: Sae 40

My 4.3L Yamaha calls for SAE 40 oil. Does anyone know where I can find it in full synthetic? The only SAE 40 oil I've been able to find is Castrol at Advanced Auto. Everywhere else I've tried has SAE 30. Nothing but "dino" oil. The oil in it right now has about twenty hours on it, and it looks brand new. I don't think I'm "looking for trouble" by switching to synthetic. I'm just looking to use what will perform best. The motor is 19 years old, and it runs like a new motor. It's aways been very well maintained and always will be. All input is welcome. Thanks.

Safe and happy boating always!!!

You can use 10/40. Doesn't have to be straight 40. Thats all I use and I never had a problem related to oil.
 

Bluestream

Petty Officer 1st Class
Joined
Sep 28, 2010
Messages
296
Re: Sae 40

You can use 10/40. Doesn't have to be straight 40. Thats all I use and I never had a problem related to oil.

I would not use 10W40 conventional oil. That grade oil will have a lot of VII (viscosity Index improvers) that will shear down very quickly. This is why 10W30 and 10W40 are not recommended for marine engines. (unless synthetic)Marine engines under high load will raise the oil temperature to the point where the VII will break down. You will end up running a 10W oil in no time, and that will not give adequate protection. Straight weight oils have no VII and do not shear down.
 

RogersJetboat454

Commander
Joined
Jul 9, 2010
Messages
2,964
Re: Sae 40

Why switch to synthetic? It doesn't make the engine go faster, get better mileage. or power. In fact I can't think of one really good reason to use it.

I can.
I get better mileage (1 mpg increase over conventional which adds up considering I commute 415 miles each week). My engines have 0 deposits in them even running at 7-10K oil change intervals. All those engine builders who pick up 5-10hp switching from mineral oil to full synthetic tend to agree that you gain power.
http://www.hotrod.com/techarticles/synthetic_vs_mineral_motor_oil/index.html
 
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