best oil for a 1985 308 qv

I am currently running Castrol's Synthetic 10w50 (or is it 0W50?) in mine. I would think any synthetic around this weight would work. The only trick is to be sure you remove the correct drain plug! The one for the transmission is often confused with the one for the engine.

Change the transaxle fluid if you don't know how old it is. Redline 75W90NS works well.

-steve

 

0W40 Mobil 1,refer to AEHas,all you ever need to know and more.

 

I use Agip SINT2000 in all of my Ferraris. It is a 10W-40 semi-synthetic and is what is recommended by the factory. No problems even with 83K miles on my 308's engine, good pressure hot or cold and pumps quickly even when the car hasn't been started in a long time.

Cheers,
Aaron
'82 GTSi
'83 400iA

 

Oils have improved a lot since 1985. Mobil 1 0-40 retains viscosity better than 50 weights at high temps in tests I have seen and you get the added benefit of better flow at low temps.

Dave

 

I use Mobil1 15w50 in my 85' 308qv. In Colorado we have huge temperature extremes from 20's-30's in the mountains to near 100 degrees in the city during Summer, I wanted something that could handle both in the SAME day. I never tried 0w-40, I guess I'm just afraid of leaks with a 0 weight synthetic.

 

10/40 Synth Amsoil

 

You won't get any leaks.

DAve

 

castrol 20/50 year 'round here at the beach. same model as you.

 

Thanks Dave, I might give it a try at the next oil change.

 

The BEST OIL is the one that begins with 0W and whatever upper number that produces the least wear on your engine and produces good flow.

Now before someone calls me a smart@$$, here is a Used Oil Analysis (UOA) from using Mobil 1 0W-40 that was used for four or so track days and about 300 street miles. Love everyone's suggestions, yet would like to see a detailed scientific analysis to back up some of the claims here of 20W-XX and 10W-XX.

NOTE: It has been reported that Mobil has changed their formula and now has less of the good slippery stuff, so am seeking something else for 2007 season. Pic below is from Blackstone Labs and taken during August 2006.

PS: if your engine leaks with lower viscosity oil, fix the gaskets and do not hide the problem by using (probably incorrect) thicker oil.
Image Unavailable, Please Login

 

What would be the recommended change interval in a gt4 ?

And would it use synthetic or dino oil ?

TIA

 

What are you doing with the car (street, track, a mix, and how many miles and time for each?

Synth imho.

 

I will be driving it on the street only.

TIA

 

Same as Aaron. AGIP SINT 10W-40

 

I just changed to castrol 10w-40 and have good pressure and I think it runs better than with the 20W-50. I don't use synthetic because I am too cheap to fix all the leaking gaskets.

 

Should anyone be interested in using a 40 weight, I highly recommend SHell's Rotella T synthetic 5w-40. The hths is higher than M1's 40 weight, and the viscocity index is about the same. IMHO, anyone who drives their 308 hard should take the hths number into heaviest consideration. The base stock used for this particular oil is the same base stock SHell uses to make Ferrari's formula 1 oil cocktail, and is the same base stock for their European Shell Helix ultra oils. If I remember correctly, the base stock is called group XIV which for all you oil heads is a group III base. Though it is not formulated the same method as other companies formulate their group III stocks. They use a very different method of isomerization and hydrocracking which they are failry secretive about.

Anyway, I do not personally use this stuff in my 308 engine, but I did use it in every Porsche engine I have ever fooled around with. My particular 308 engine has 79k miles on it, and I think I will stick with 20w-50 because that is what it has always had (the one and only mechanic who ever worked on it said so).

Rotella T synthetic can be purchased in a large blue gallon container for $14 exclusively at Walmart.

 

EXCELLENT suggestion and one of the front-runners for what i may use in 2007. The other oil is the famous German Castrol, though want to be careful about going TOO LOW a viscosity and want to be sure i get flow. Oil baffle has been modded to reduce oil starvation.

davidbealGT4, since you live in San'd i feel Shell's Rotella T synthetic 5w-40 oil should be fine. Remember to use the Baldwin filter and change oil somewhere around 4k miles or 6 months. Run her hot every now and then using the 'Italian tune-up' method (choose 2nd or 3rd gear and let her stay around 6.6k rpm for a minute or to).

 

I have had nothing short of fantastic results with the Rotella T synthetic. Oil consumption on the track went down when I changed my 911 to it from M1 0w-40. At the track, I would burn at least 1 quart of M1. When I switched to Rotella T, consumption went down to 1/2 quart, if that much. I also read that the higher copper content in Rotella T synt is better for engines with flat tappets such as ours.

 

SOLD! i'll pick some up next week on my way back from my Mon/Tue track event with my open wheel track car.

 

Hey, let us know how it works out. I might just put it in my car after all too.

 

I live in Colorado too and I'm sold on Amsoil 5w-30 synthetic year around. I change oil once a year.

 

I hear Amsoil uses a huge amount of additives that may be unhealthy for engines that burn a little oil. As in, the cats may be affected. No proof for any of this, but that is what I hear.

 

I haven't heard that about Amsoil. In the extensive research I've done you learn that all oils have additives and the high VI index of the better synthetics means these additives last longer and do an excellent job of lubricating long after lesser oils have run out of their additives and thus lubricarting abilities. I'll check into it more just to see though but I think Amsoil is one of the finest oils you can buy.