Motor Oil Type

[ag4ever]

I was going to do an oil change today, but when I went to buy oil I could only find Penzoil in straight 40wt as recomended in the owner's manual. I decided to hold off on the oil change because I find it hard to believe in this day and age that an engine should be run on straight weight oil. (I also don't care for penzoil, but know it is just fine to use.)

Now my question is:

What weight oil do you use?

Does anybody run synthetic oil?

BTW, I have the excalibur 330 in my '02 SANTE.

[NautiqueJeff]

From the Excalibur Owner's Manual:

[skinautique]

Run straight 40 weight high performance or straight 30 weight high performance oil.

[ag4ever]

Were there any changes from '02 to '04 that would change the oil weight requirements from straight 40wt (above 50 degrees) to the 15W-40 that the excalibur "owner's manual" dictates. I don't even remember gettin an excalibur owner's manual, and am just going by the CC owner's manual that I got with my boat.

[skinautique]

The engine manual should be in with the correct craft manual. I have always run straight 40 or 30 weight HP oil in my old 02 excalibur and the 04. No problems ever.

[tryan]

i run a straight weight oil, but only in a 20 degree temperature window of 70 to 90 degrees. if you get out in the morning and it's 50 degrees or so, run a multi-vis oil. there are advantages to building pressure quicker with a multi-weight oil.

i have not read the bottle on the straight weight, but i doubt it's sj. you can run synthetic oils, but an engine oil cooler would be a better investment. imho.

kendall or redline

[wburg64]

Mineral, synthetic, ashpalt lots to know about oil they all are not equal.
Go to www.micapeak.com/info/oiled.html

[ag4ever]

The dealer sadi they use straight 40wt, and since I want to be good with the warranty, it will have straight 40wt in it at the next oil change, just like the dealer did at the last oil change.

BTW, in texas where I am, there are not too many morning where I am in 50 degree weather. Around here it is usually hot, hotter, or **** when is this heat going away.

[tryan]

if you are doing your own work on a warrented motor, leave a paper trail and do exactly as you owners manual perscribes.

don't use penzoil. it sucks at high temp from my personal experience on a few air cooled cars.

[TwinTip]

Besides considering the temperature and classification/viscosity (assuming the same will apply to all brands of oil), what brand do you all recommend?

Is this recommendation based on preference or actual quality/performance of a certain brand of oil?

[ag4ever]

I went one step past documenting it. I took an oil sample too, and will continue to do so at each oil change. I want to know how my engine is doing well before any possible engine failures.

I use Blackstone Laboratories for my analysis. The cost is only $18.00 when you mention thedieselstop.com. I feel having a list of oil change analysises will go miles if there is ever any questions.

I have decided that engine oil v-drive and trans fluid changes are best left to the dealer after the first set I did. The engine oil change is not that bad, but the tranny and v-drive were a b1tch!

[nms1991]

mark your oil filter with the hours and date when you changed your oil, also dont use the cheap 89 cent oil because it is most likely recycled oil. But tryan i had a 1991 chevy truck with the 305 with 254,000 miles with no problems using Penzoil and it is still running with close to 280,000 miles( valve covers never been off) and still pulls boats with no problems, still runs with 35 to 45 psi oil pressure.

[tryan]

choosing a brand of oil is like asking someone what kind of beer they like. some people drink bud and others drink amstel light.

there is a lot of information out there, but it alls boils down to personal prefrence and experience. if you want to study up on long chain, short chain, cracked hydrocarbons, saybolt seconds ect, go for it. my philosophy is to run dino oil in the old ones and synthetics in the new ones. what ever brand came in the car motors from the factory is what gets poured in. the nautique gets kendall straight 30wt.

the most important thing for engine and oil longevity is to maintain the oils temperature in the 180* to 200* window. you have to get it hot enough to cook off the moisture or the motor will sludge.( my mother ran havoline exclusivly in her buick with a 350 for 250k without issues, but the motor was pretty gummed up internaly from driving 5 miles/ 10 minutes and shutting it off.) if you putter around with a cold engine or live at the redline, i would change it every 6th or 7th tank of fuel.

if you slap an oil temp gauge on the motor and you hit 240*, a cooler would be a wise investment.

i recently switched from ford oil to shell rotella in the powerstroke. fuel economy went up 10%+. no bs.

motor oil is motor oil. you can pay me now or pay me later.

[NautiqueJeff]

PCM has revised their oil recommendations, so I wanted to update this thread so that people searching for this information would get the latest.

[jhiestand]

Anyone know if the PCM revisions include older motors like the GT40, or just for the newer GM's such as the Excaliber?

I've been ever faithful to PCM's recommendation of straight 40 weight for my GT40 but it's not available everywhere and I'd switch if PCM said multigrade should be used instead.

[NautiqueJeff]

I would think that these new recommendations only apply to the newer GM engines.

[DavidF]

My take: PCM finally updated their antiquated oil recommend to coincide with modern oils. I 100% agree with the new recommendation for new engines. IMHO, once the engine hours climb significantly (the equivalent of 50,000-75,000 miles) then I would switch to 20w50.

Also IMHO, I think PCM not recommending synthetic is due to their VERY conservative change interval. Synthetics (again IMHO) are superior oils to dino oils. And before anyone goes off on argueing this comment, I have already heard it all.

I live in Austin, TX and run 20w50 exclusively (yes dino because it is cheaper and I change the oil annually so no worries with using up the sludge preventing additives) and have been for over three decades on three different boats with nary an oil related engine problem.

[ryanandrews]

jeff- i got a 1994 , what oil and tranny fluid did you run in yours?

[NautiqueJeff]

I ran straight 40 wt. in mine, with Dexron III in the trans.

[boysrus]

After many years of straight 40 weight in all my boats (28 years worth) - I just made the switch to a multiweight synthetic in my GT-40. Time will tell if was a good decision or not... I did it mainly based on forums like this for turbo diesels. Since those engines see hard use like our boat motors, and most of those manufacturers are recommending multiweight synthetics - then their time must have come. The temp ranges here in Colorado are the main reason I went looking to change. I am, however, sticking with the 50 hr change interval. I'm not that comfortable yet!

[jedgell]

Boysrus,
What multiweight oil are you using in your GT-40?

[SGY]

Boysrus, where in Colorado are you?

I spoke with Richard at Skidim two days ago. He still recommends the straight weight oil in the GT-40--as do PCM and Ford.

it is impossible to find a straight 40wgt oil nowadays. I have found 0-40 synthetic, 5-40 synthetic, 15-40 dino, but no others. I have run 0-40 and 15-50 synthetic in my GT-40. I think the best would probably be 5-40 synthetic. You get the flow characteristics of a 5wgt when cold, and a 40 wgt when hot.

My Duramax calls for 15-40 dino or 5-40 synthetic, a diesel engine works hard just like a boat. When Mobil has there 5-40 available I will run it both in my boat and truck.

Sythetics are better, it has been proven. I think PCM does not recommend them because of the extended drain interval. I just run it and change it at the recommended interval.

good luck :grin:

[skijones]

I run all kinds of equipment on 15-40, usually Rotella or Napa brand. Never had any kind of bearing or wear problem. If diesel and big pickups run on it, I can't see why it would work in a small block gas engine.

My old 85 has 800+ hrs on it now, does not use any oil and runs like a champ.

[boysrus]

Yeah - I realize a 40W is still recommended, and I was very nervous about switching... but the cold temps had me nervous about continuing with the 40W. That, and I figured technology has to be improving past the old straight weight dino oils. In fact, Cummins recommends synthetics in my new Turbodiesel, my new dirt bike REQUIRES synthetics (another severe service application) as does my wife's car. It seems that most high tech applications are going that direction.

So - I really can't recommend it to anybody else, just consider it an experiment (hopefully with a good outcome...).

I'm using Amsoil's Diesel/Marine 15W-40. I'm in no way an advocate of Amsoil, but they and Mobil1 have been making the stuff as long as anybody, and there wasn't a Mobil1 for that application yet.

I'm up in the NW corner of CO - Rangely. We have a small lake with a slalom course - so when it isn't frozen, life is good!

[SGY]

Boysrus, you ever make it down to Denver?

[boysrus]

SGY - I get over there a few times a year, but not too frequently. We do have relatives and friends there.

Is that where you're at? If so, where do you ski over there?