engine oil

[mamovaka]

guys,

can you help me out on what is the best motor oil for the v8 under 450hp conditions?

Pano

[andrewp1989]

With stock horse power I am using 5W50 and worry that it is too thin an oil. The original owner used mineral 5W30 ($14 a jug junk at Walmart) and it was much too thin. Two or so oil changes with 5W50 should clear out that mixture from the oil coolers and oil lines. Mobil 1 is still my favorite.

With 450 HP I would go for a heavier oil like 10W50 or perhaps 10W60 (this a BMW specific oil) but I'm sure someone will flame up for this suggestion.

AP

[Bibs]

Lotus recommend Castrol Edge Sport 10W60 for the V8.

[redshift]

Lotus recommend Castrol Edge Sport 10W60 for the V8.

That's what I always use too.

[fmxa]

Best I've found in the US is redline 15/50 http://www.redlineoil.com/

[BobG]

Well, I am using Mobil one 15/50 and although I have not noticed anything amiss I am a bit worried it's not thin enough- less protection on startup particularly as I don't use the car every day.

Bob G

[Bibs]

Drop it and use the recommended oil Bob, you'll sleep better

[Iconic Ride]

Bibs, though I assume the Lotus dealer would be able to procure it, finding Castrol 10W60 on one's own in the US is problematic at best. Would the BMW oil (developed for the M5 I believe) with the same viscosity numbers (and, as far as I know, is "fully synthetic"--keeping in mind that the definition of that term is open to interpretation, depending on the manufacturer) work as well, or is there more to "Edge Sport" than just the numbers?

[73JPS]

I don't suppose I have the most current info, but this is directly from the V8 shop manual I have: "Lotus specifically recommends the use, in all climatic conditions, of Mobil 1 5W/50 or 5W/30." Castrol is listed as an "otherwise one of the following...should be used" oils, not THE one to be used.

I presume (from Bib's post) that the oil recommendation has changed because of technology, and fair enough, but I cannot possibly see that the use of the oils recommended when the V8 was conceived would be detrimental to the life of the engine.

My engine has been run primarily on synthetics from Royal Purple (previous owner) and Texaco (as input by my local Lotus dealer), neither of them on the "recommended list". After 28,0000 miles, leak down tests show my engine to be in excellent health... for what it is worth.

Edited June 30, 2009 by 73JPS

[superdavelotus]

I always swear by Mobil 1 15/50 motorsport.

David Walters

[Bibs]

Lotus recommend Mobil 1 5W/50 or 5W/30 for the V8.

Swearing by it is all well and good but have you done as many tests and do you know as much about oil and the engine as Lotus and Mobil? What was your budget for testing oils? What parameters? Lotus put these engines on dyno's for thousands of hours, spent 10's of thousands of pounds and recommended lubricants are also selected in conjunction with the oil companies.

[73JPS]

Bibs,

Not that I suppose I would be able to find the stuff, but can you clarify from your earlier post if the recommendation to use Castrol Edge Sport 10W60 is a factory update that supercedes the manual? Thanks.

[Bibs]

Patrick, that is correct.

[73JPS]

Thanks, I'll see if I can source it here