Gt40 oil change

[rodltg2]

I know it recommends 40wt. But could not find it. Can I safely use this ? Pros cons ? Also was given a Wix filter as the cross reference for motorcraft . Good ?

I'm at higher hours close to 1800. Warm weather for awhile longer.

 

 

 

[oldjeep]

Any auto parts store or fleet farm will have 15W-40 rotella T for about $4 a quart

 

oreillyauto oil

[Skoot1123]

I just changed the oil on my GT-40 and used Rotella 15W-40 oil for it. Engine is running great on it.

[Shell]

I just bought and changed the oil , Rotella 15w-40...@Oreilly Auto...along with Wix filter, and tranny fluid....

Complete change last weekend, engine running great!

[foxriverat]

I get the VR1 straight 40w from napa. They usually only have 1 partial case if that. If they dont have enough they order another case from their warehouse and I pick it up the next day

[BrennanKMN]

Like @foxriverat I get my VR1 40w from Napa. Just did an oil change on my GT-40 last weekend. I also use Motocraft FL1A oil filters. About 5 bucks a piece at the local Ford dealer.

[rodltg2]

Isn't it for diesel trucks ?

[oldjeep]

@rodltg2 that is what they primarily sell it for, but many boat owners and dealers use it. My Indmar specs 15W40 Marine Pennzoil which is nearly impossible to get this year for some reason. Rotella seems to be what most folks have been using anyways since it meets all the required specs (SM CJ4). Some of the earlier versions of Rotella had a warning about use with catalytic convertors but the current T4 15W40 does not.

[Stickman]

Have a real Auto Parts store order you a case of staight 40wt (Valvoline). Motorcraft FL1A.

[Bruce_Butterfield]

As far as the weight goes 20W50 is fine. A lot of gearheads would say it's better. The bigger issue is the 351 has flat tappetts that requires additives that are missing in most modern oils (zync something if I recall). VR1 is one of the few oils that has the additives the GT40 needs and probably the best choice overall.

 

There was a long discussion on this a few years ago and is probably in the archives if you are really interested.

[BrennanKMN]

Diesel oil has the zinc needed too, that's why a lot of folks use that in place of VR1.

Shell Rotella T has 1200 ppm Zinc. Valvoline VR1 has around 1400 ppm Zinc.

[BraceMaker]

B.O.S. normally avoids Oil Threads.

 

My theories (not an oil specialist) usually run towards the concept that straight weight oils hold up best due to the lack of modifiers. A 20-50 is 20 weight oil that has modifiers inside it that make it act like a 50WT oil when hot.

 

So 20-50 probably OK, 40 WT probably very good oil for the application - I would bet that if you run in very cold water that you might want to run a 15-40 or 20-50 just so that the start up is easier.

 

When I used to run old BMW motorcycles those were the worst oil shamers. Would buy everything from Kendall to VR-1 to specialty formulations. Ultimately I switched to Rotella T as well even though many claim it doesn't have as much ZDDP as racing oils.

[ski6jones]

Been running the VR1 in my GT-40 for about the last 10 years. No issues. Using it because of the issue cited by Mr. Butterfield.

[JAG]

+ 1 on the SHELL Rotella. 800 hours on my 2002 PCM 350 and zero oil use. I think it runs better now than when new actually. Hard to beat a small block Chevy. :D

[Justin_C]

I second the Rotella

[6balls]

Just had a mechanic tell me that racing oil does not last like other oils as it's designed to be changed more often like in race cars. I have been using racing oil for changes, but he recommended rotella for the GT40.

 

[BraceMaker]

He is correct. Somewhat academic.

 

Racing oils can have great levels of the good stuff, antiwear additives. Which we like for keeping our cams in good order.

 

They don't however need to have additives which control how corrosive the oil becomes as it ages. Consider it like a pH buffer in chemistry. Road oils need to protect a mildly used engine against months of cold starts around town use with few instances of heavy use. Over that time the additives need to prevent moisture and contaminant build up from causing damage - including having detergent levels to keep stuff moving into the filter.

 

Race engines need the opposite - tons of antiwear additives in oil that is changed after the race and never sits.

 

 

Rumor has it that rotella and other diesel oils like Delo have cut zddp with the addition of cats and def over the years which... I use rotella anyhow I'm cheap and it's on Amazon prime subscription so it shows up with a filter right before I winterize.

 

I doubt anyone will have an issue with vr-1.

 

Maybe a poll but I'm sure this forum has thousands of cumulative hours of engine running.. anyone wear out a cam? What oil was it?

 

 

[jpattigr]

Rotella T 15-40 in my 351, called PCM many years ago and they recommended the oil highly. Engine runs perfect.

[skiermanbrad]

I called PCM before my last oil change and the person I spoke with recommended the Rotella.

[paco]

@rodltg2 The Valvoline 20w50 you pictured is better for your engine than the rotella. Not saying rotella is bad oil, I currently use it in all my diesel engines, but the zinc level is lower in it than in previous years. This is why most will recommend rotella. Another good recommendation for your engine is Mobil one 15w50, also high in zinc additive for your flat tappet cam engine.

 

Main thing is you care about maintenance, no matter which oil recommendation you use, regular maintenance is by far the most important! Oh, and don't use fram oil filters ;)

[Fast351]

But the PCM GT40 service manual says PH8A (Fram) specifically!

 

It actually does, but I know what you're saying. The Motorcraft FL1A is regarded as one of THE best oil filters in that size. I researched it a ton when I was racing 351W engines, and always ran Motorcraft filters.

 

An interesting link from a long time ago where a guy cut apart about 30 different filters and looked at the construction and size of filter media: Filter study (Short link just for @Horton :smile: )

[rodltg2]

Decided to go with the rotella. Changing oil tonight while enjoying the great view of the backyard. Here's to some great fall weather !

 

 

[LeonL]

It says right on my oil filler cap 15w40. '08 196 with 5.7. So I use diesel oil. Sometimes Rotella , sometimes Mobil Delvac. What Nautique recommended for the GT40 I don't know. Doesn't it say on your cap? I've know of a couple of guys who use synthetic, put 50-60 hours a year on a boat and then change it at season end anyway. A waste in my opinion,

[Jmoski]

owners manual on my old GT40

powered SN said "40w40." Straight 40 doesn't work in the north when skiing in November, so I always ran 15w-40 Castrol GTX which has 1300 ppm of zinc...

 

don't let the diesel label fool you on the various 15w-40 brands - the fine print states it's good for conventional gas automobiles as well.

[Drago]

so should the Rotella be VR1 or are other Rotellas good?

 

[208skier]

VR1 is not an oil specification applied across brands. It is how Valvoline denotes its racing oil.