Valvoline 20/50

[FlyLo]

Just had the 1k service done. Dealer used Valvoline synthetic 20/50. I asked about this.

Reasoning is this: Lower weight oils are recommended by manufacturers for the purpose of getting a better CAFE rating, whereas 20/50 has yielded a better experience in engine wear. Note, this is in an area where the temperature NEVER gets below 20 degrees F. His recommendation would be different for colder climes.

His experience is that the higher weight oils prevented a lot of otherwise common problems with his Aston Martins which were later determined to be caused by lubrication failure. After reading the Toyota engine service manual, he decided to stick with it for the Elise.

In colder climates, 5-40 synthetic makes a lot of sense.

[Johnny B]

Originally Posted by FlyLo

Just had the 1k service done. Dealer used Valvoline synthetic 20/50. I asked about this.

Reasoning is this: Lower weight oils are recommended by manufacturers for the purpose of getting a better CAFE rating, whereas 20/50 has yielded a better experience in engine wear. Note, this is in an area where the temperature NEVER gets below 20 degrees F. His recommendation would be different for colder climes.

His experience is that the higher weight oils prevented a lot of otherwise common problems with his Aston Martins which were later determined to be caused by lubrication failure. After reading the Toyota engine service manual, he decided to stick with it for the Elise.

In colder climates, 5-40 synthetic makes a lot of sense.

I've owned a Ford that called for 5w-20 and now have a Dodge that specs 5w-20. There's no way in hell I'm running something that thin in this hot of a climate. Ford, Dodge and the others are all specifying thin oils for CAFE numbers. I'm running Mobil1 5w-30 in the Dodge.

I'm running Mobil1 15w-50 in my Elise and changing my oil every 3k miles since the coolers aren't drained. If I remember correctly, we can run a 10w-60 per Lotus if running the car hard on the track.

[FlyLo]

On a tangent: Do modern engine temperatures really vary much by climate? The cold temp on start up, obviously, but at operating temp?

[TimMullen]

Originally Posted by FlyLo

Lower weight oils are recommended by manufacturers for the purpose of getting a better CAFE rating, whereas 20/50 has yielded a better experience in engine wear. Note, this is in an area where the temperature NEVER gets below 20 degrees F. His recommendation would be different for colder climes.

Yea, but...

Many manufacturers are recommending 5W30 or even 5W20 in large part because of the CAFE (Corporate Average Fuel Economy) ratings. However, Lotus doesn't need to worry about CAFE ratings (our car already exceeds the required standards, and since they only sell one model, it doesn't need a low rating to off set a gas guzzling SUV's poor mileage). Lotus requires 5W40 oil which is already "thicker" than most manufacturers use in their engines.

Modern engines (including ours) are made to much tighter tolerances then in the past, and as a result, don't need "thicker" oil to "fill in the gaps" in the bearings - in fact, they need the proper "thinner" oil to flow properly to all internal parts of the engine. 5W40 is probably the proper "thickness" of oil for our engine for all around use - you might want a bit thicker for serious track use, but that's it.

Just because an Aston Martin service manager decides to use a thicker oil is not a good enough reason to over-ride what Lotus recommends.

[psionix]

contact lotus @ 1 800 245-6887. they'll get in touch with the dealer and make them give you the right weight oil and a free oil change... someone else on here had similar circumstances but i can't seem to find the post ATM.


edit~ found it: http://www.elisetalk.com/forums/show...2&postcount=22

[FlyLo]

It's hot here. I track my car. I'm happy with 20/50.

[etypeiii]

I am not certain how a 20-50 oil provides more protection for the engine in hot climates. These oils are multi-viscosity, which means a 5-50 oil has the same thickness at high temperature as a 20-50. It just flows easier when cold.

With conventional oils, such a wide spread of viscosity range is accomplished with additives that break down. Thus, using a conventional oil, a narrow range is "better" provided climate conditions allow, because it needs less viscosity index improver due to the narrower range. But synthetics do not require much, if any, viscosity improvers, so there doesn't seem to be much advantage to running a 20-50 in hot climates.

If the engine requires the lower viscosity at cold for lubrication due to tight tolerances (which I do not know is the case for the 2zz engine, though many have indicated it as a possibility) a 20-50 would be a detriment.

As far as manufacturers just specifying "thin" oils for gas mileage, with no regard to longevity - most manufacturers have 7/70,000 mile engine warranties (i.e. far longer than they offered 15 years ago) so I don't know that they don't care about engine longevity. Of course Lotus is only 3/36,000, but I'm sure Lotus doesn't have to worry about CAFE too much...


DLY

[billstock]

Toyota calls for 5-30 for the 2ZZ. I agree that this is at least partially driven by fuel economy concerns.
5-40 Mobil has shown some of the best wear numbers among current oils. See: www.bobistheoilguy.com

[JnC]

Random thought: The more the oil departs from it's natural viscosity, the more additives are used. Additives do not lubicate as well as oil.

[etypeiii]

As I mentioned above, a proper synthetic oil will require very little to no additives to achieve a broad viscosity range. It's "all oil", so to speak.

As this is what is specified for the Elise, I would think there would be no problem at all.



DLY