Found this on a Mitsu FTO site. Interesting read, I'm not offering a comment either way .... teflon shoulderpads on

More on oil - here's an email from Mobil
[from the Technical Manager for Mobil Oil]
The Mitsubishi FTO is a high tech engine with the latest design and best materials in construction. When new, the engine is clean and tolerances are fine. Common sense suggests that to keep it like this and in tune for best performance you have to use a quality lubricant.

The most stable products on the market and those which are being chosen by manufacturers for extended service are fully synthetic PAO (PolyAlphaOlefin). This includes Castrol SLX, Esso Ultron and Mobil 1. These products are extremely stable in extremes of performance. Next consideration is viscosity. At the low temperature end you need a 0W to give the best flow around the engine and ability to satisfy hydraulic tappets and variable valve timing.

Note: 0W is not thin when cold. It is just thinner than higher numbered oils, in fact it is around 10 times thicker at 20 degrees than the oil is when at 100 degrees. For best high temperature performance you need an oil which has a High Temperatre High Shear (HTHS) rating of 3.5 minimum. This will usually mean a 40 weight oil. The high quality base oil and strong additive package make sure the oil does not shear and become lower than this figure. If it does, you have wear at best and siezure at worst. So there is the case for Mobil 1 0w-40. If it were my road car, and I drive enthusiastically! I would use Mobil 1 0W-40.

However if you do not have low temperature situations, or care not about start up fuel economy, and run your FTO as an ultimate ***** out rally car, then Mobil 1 Motorsport at 15W-50 may be the way to go to give you ultimate protection at the limit (thicker oil film at highest temperature and power).

For your interest the product being promoted by Mitsubishi dealers (Castrol Magnatec) is offered to maximise profit potential from a relatively inferior cheap product. It is a mineral oil with a small percentage of non PAO synthetic to allow the not so low rating of 10w. Sure it will work and the engine will not sieze up. But consider the longer term !! Why do Castrol have a top tier SLX grade. And why are they launching a 0W-40 SLX onto the market. To copycat Mobil 1 0W-40 !!

 

My local dealer is using Mobil1 5/40w.. seems ok..

 

Since when was the FTO a rally car ?



Cheers

Ian

 

Useful email. Cheers.

 

This seems to be the most significant part:

"15W-50 may be the way to go to give you ultimate protection at the limit (thicker oil film at highest temperature and power)."

The FTO isn't turbocharged so the oil gets a much easier life, less exposure to very high temperatures. This is taken from the Mobil 1 technical data sheets:

When exposed to a temperature of 250C for just one hour:

Mobil 1 0W-40 loses 10.5% by weight.

Mobil 1 15W-50 loses 5.5% by weight.

Quite a difference isn't there. Hats off to Mobil for having this type of information available on their website. I'd love to know what the weight loss is on some of the semi-synthetic oils.


[This message has been edited by Andrew Timmins (edited 22 February 2001).]