garrett376

I just saw that costco carries a version of mobil1 with the 15w-50 weight (has a red box versus the blue or green one) - this sounds like it would be ideal for a car driven hard in hot weather, no? I have usually filled with the Mobil1 5w-30 - is the 15w-50 a better oil for a race car driven during the summer heat (100 degree air temps?)???

I am curious what ya'll think. I have some oil changes coming up for the new engine soon and this sounds like a good choice...

ilko

Here's a discussion on the 993 forum about the Mobil 1 15W-50 oils with tons of links and info. It'll probably make your head hurt, but here it is: https://rennlist.com/forums/993-forum/336898-mobil-1-15w-50-vs-15w-50-extended-life.html

Geoffrey

Garrett, the 5-30 will provide more power (measureable on a dyno), however, due to the temperatures and our "cost budget" I suggest running 15-50 because it provides better protection. The 993 has hydraulic lifters and the thinner oil is recommended by Porsche.

Nader Fotouhi

OT, I heard that Costco in VA/MD has 15w-50 on sale. If the bottle caps are red, grab the oil. You can make a couple of bucks re-selling the red cap 15w-50 Mobil 1 in 993 forum. LOL

If you have used 5W-30 in the past without issues, why change? Have you considered 0w-40? That said, most racers/track guys I know on the East coast use heavier oil than 5W-30. I have been using 15w-50 in my 944S2. About 20 race/DE days last year and I only added 2 qt of oil to the original engine with over 100K (Knocking on wood). I also changed the oil in the 964 which sees some DE to 15w-50 as soon as it arrived. On cold mornings (below 32F), wife waits about 30 seconds before rolling and keeps revs below 3-4K to allow the oil warm up.

Mobil 1 oil's recent varieties (5000, 7500, 15000 miles) reportedly have reduced Zn and P which are the antiware agents (see 993 forum in depth discussion mentioned by Ilko). The old 15w-50 formual (API/SL) had red cap. The new 15-50 formulation (API/SM) has gold cap. I used the red and did not really have a chance to change the oil all summer last year and the oil still looked fine. I will not likely repeat that experiment this year regardless of cap color.

garrett376

Thanks guys, and thank you Geoffrey for the valuable suggestion - I'll follow it

kgorman

I have been running 0w-40 per the oil spec Jason posted. Car seems to like it. I am not sure if it's ok for the hot Buttonwillow and Thunderhill summers though. I might go back to 15-50

Steve Weiner-Rennsport Systems

FWIW,.....Don't go by cap color,...

The older SL-rated gold cap 15w-50 M-1 formulations are OK. The only way to tell what you are buying is by the API designation; SG-SL-SM, etc.

Mobil has reformulated the 15w-50 M-1 and Charles Navarro is retesting to confirm the added ZDDP content. Read the http://www.lnengineering/oil.html to see whats what as well as some excellent threads on Pelican's 911 Forum that are very informative. Oils chemistries have changed and one needs to get an education to know what you are buying.