Hybrid240z Posted April 21, 2002 Share Posted April 21, 2002 My 240Z has a L28 block, E88 head, Moon cam and triple SK carbs. What oil weight should I use, 10W-30, 10W-40...and why. What are the advantages/disadvantages. What engine setup do you run and what oil do you use. Any suggestions will be greatly appreciated. Thanks, Marcos Quote Link to comment Share on other sites More sharing options...
Mike C Posted April 21, 2002 Share Posted April 21, 2002 I run 10w40 in most of my cars. It is a good compromise between high viscosity and good thermal performance without being too thick for winter time use. In LA I would run same. There is more power to be had with lighter weight oils however, and if your engine is in really good condition, it may be worthwhile to run a 5w30 synthetic. I run 20w50 in my air/oil cooled FJ1100 and in my Camaro. Straight 30w in most of my small engines (as recommended by manufacturers) and straight 40w in my 5.7l Malibu boat, once again as per manufacturers recommendation. I have not made the transition to synthetics and usually do 5-6k mile oil change increments except for the boat and the bike. Quote Link to comment Share on other sites More sharing options...
fl327 Posted April 22, 2002 Share Posted April 22, 2002 im a mobil 1 synthetic 15w-45 red cap guy in cars that i like to drive hard and really cherish. everything else gets flag 10-40. Quote Link to comment Share on other sites More sharing options...
Hybrid240z Posted April 22, 2002 Author Share Posted April 22, 2002 Really good weekend. Worked on my 240Z and drove it Saturday and Sunday for more 150 miles. Man, it hauls "behind". The engine is tight and in really good condition. I am going to be running Amsoil synthetic oil. Which weight should I go with. Thanks, Marcos Quote Link to comment Share on other sites More sharing options...
Hybrid240z Posted April 22, 2002 Author Share Posted April 22, 2002 Oh, forgot to mention. Amsoil carries 5W-30, 10W-30 and 10W-40. They also carry a fuel efficient formula, 0W-30. I run that in my Accord but I think that would be too light for the 240Z. Any suggestions? Thanks, Marcos Quote Link to comment Share on other sites More sharing options...
DAW Posted April 22, 2002 Share Posted April 22, 2002 If the Amsol choices are the only ones you're selecting from, 10W-40 would be the best, if the engine has high miles then 20W-50 in Southern CA may be better. DAW Quote Link to comment Share on other sites More sharing options...
Hybrid240z Posted April 22, 2002 Author Share Posted April 22, 2002 Well Daww, I forgot to mention the 20W-50 Severe Service Synthetic Racing Oil. I didn't mention it because I thought it might be too thick. Isn't it. Do you lose horsepower by running this weight, are there disadvantages. Why is this weight considered a race oil. Marcos Quote Link to comment Share on other sites More sharing options...
DAW Posted April 22, 2002 Share Posted April 22, 2002 Racing engines see severe loads/heat, need to ensure higher oil pressures, and often have clearances toward the larger end of the ranges and these factors demand higher viscosity oil. This is my opinion, so engine-builders correct me if I'm wrong. You haven't said how many miles are on the engine. I usually run 15W-40 Castrol semi-synthetic until the engine has 75K miles, then go to 20W-50. The lower number, 10W, 20W, etc is important regarding what climate you live in and what temp the cold starts are going to occur at. In Southern CA you could run 20W- all year; a bad idea in Fargo, N.D. in the winter. DAW Quote Link to comment Share on other sites More sharing options...
Hybrid240z Posted April 22, 2002 Author Share Posted April 22, 2002 Well the engine has about 30k miles on it after the previous owner built it up. The engine runs very cool at idle and cruising speeds, but I have only had it a few weeks. I did see it go higher yesterday when I was racing the engine. I hit 115mph and was hauling for a couple of minutes. The temp creeped up but not very close to halfway mark on the original guage. The car has a 3 core radiator and original fanclutch but it is missing the fan shrouds, imagine that. And it still runs cool. I want to install the electric Black Magic fan that I have. I guess I don't want to run 20W-50 oil unless I have to or really should. I was thinking 10W-30 or 10W-40, but which one should be better for this application. Thanks Daw, Marcos Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted April 22, 2002 Share Posted April 22, 2002 As a lubrication professional, I feel I must chime in here with a word of caution about 10W-40 oil. Multi-viscosity mineral oil (not synthetics) are made by adding polymers to a base grade of oil, in this case 10W. As the oil heats up, the polymers, like little phone cords, uncoil and create resistance to flow, and thus make the oil behave like a higher grade oil at high temperatures. In order to make 10W-40 oil, you have to add a LOT of polymer, which in a given volume of oil, displaces the actual lubricant, the oil itself (polymers themselves do not provide lubrication). Auto manufacturers do not recommend and sometimes specifically say "do not use 10W-40", as is the case with my '91 Chevy truck. Take a look at your owners manual for those of you that have other more modern vehicles. For an older vehicle in a mild, or summer climate like SoCal, 20W-50 is fine. For new vehicles, and colder / winter climates 10W-30 or even 5W-30 is recommended. 10W-40 is still around because old habits die hard. The public still clamors for 10W-40 because it was the first multigrade oil available, and is the first grade that comes to mind when people think of oil. You may say "Ok 20W-50 is a 30 point spread just like 10W-40, how come 20W-50 is OK?" I'm glad you asked! Viscosity grades are not linear like that. It takes much less polymer to make a 20W behave like a 50 grade at high temperature than a 10W to a 40 grade. Of course, if you use synthetics, all of the above mumbo jumbo is off. They engineer viscosity control at the molecular level and do not use polymers. Quote Link to comment Share on other sites More sharing options...
Hybrid240z Posted April 23, 2002 Author Share Posted April 23, 2002 Good source of info for those not running synthetic oil...what synthetic weight do you suggest Greimann. Marcos Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted April 23, 2002 Share Posted April 23, 2002 Go with the 20W-50. It is a good southern California climate performance grade. Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted April 23, 2002 Share Posted April 23, 2002 Stupid Netscape duplicated this post. Quote Link to comment Share on other sites More sharing options...
Hybrid240z Posted April 23, 2002 Author Share Posted April 23, 2002 Hey Greimann, I just noticed that you live in Huntington Beach. I work in Newport Beach. I wouldn't mind checking out your Z. I will be taking mine to work tomorrow. Maybe I can pass by on the way home from work. My e-mail is lt1240zmech@hotmail.com and my aim user name is lt1240zmech. E-mail me or chat online if you think you have a chance tomorrow. Thanks for the info, Marcos Quote Link to comment Share on other sites More sharing options...
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