Castrol Magnatec 5W30 fuel saver oil - anyone tried it?

[LeroyPatrol]

I was in SuperCrap the other day and saw this Castrol Magatec 5W30 fuel saver oil. I've been running Magnatec 10W40 in the old VT Commodore for years and have always gotten good mileage. My theory has been, with the engine wearing as it gets older, there is less friction and hence I get better mileage. It uses around a litre of oil between changes, blows no smoke but the old girl has 275,000 km's on the clock! I also run my tyres at 40psi. If I drive nice on the highway I can get less than 9l/100km's but always get around 9.5 without trying. Not bad from a 12 year old car! I don't think I'm game to try the 5W30.

Leroy

[Godzilla]

Use the thinner oil on newer engines.

Most modern engines run 10-30, the lighter oil reduces friction and oil slosh resistance giving better mileage and more engine response and power.

Stay with a thicker oil on worn motors as you need a layer of oil to keep parts separated and take up wear that a thinner oil cannot.

You may even notice a drop in oil pressure due to it being too thin and just running out of the excess clearances.

I use Nulon Synthetic (semi) 10-30 low friction oil on engines, but modern ones.

[Redwight]

If it uses oil between changes as stated it will suck this stuff out the exhaust if you use it. I used some 5W/40 synthetic blend in my EB 4.0l engine and it was the only oil I stuck in it that it consumed, everything heavier was fine.

[LeroyPatrol]

I was already thinking of going to a slightly thicker oil after winter because of the age of the engine and after winter because this is what I have to use to get to the snow at the moment.

Leroy

[Godzilla]

Just watch when using Full Synthetic oils on older engines, you may suddenly discover new oil leaks that were never there before.

[RISKY_B]

what ever Godzilla says you can bank on !!!
id stick with the 10/40
in my vx 200,000 im still using the 10/30 but now it's at that k's im think of going 10/40
a low vis oil dose help a little with power and econ but at that k's will not help anything and no point putting in a full syn
in my old engines i run a good mineral oil with a hight level of zink for good liffter and cam life thats in my air cooded flat 4 single under head cam and L18