what weight oil works best in the 2.5? im partial to castrol gtx magnatec, used it in a few of my previous cars. usually 5w30 does the trick and releases a few extra ponies. is 5w30 fine for the 2.5? oh and how much oil does the engine take after draining the old stuff out and changing oil filter.

Oil releasing extra horsepower? New one on me.  

I use Vx semi synthetic 10w/40. Good stuff,  a damn site cheaper than Castrol and does the job very well.
However I have to add I change my oil and filter every 3-4 months or 5,000 miles with out fail.

Oh and the V6 takes 5.75 litres from completely empty

Or tesco's

Taxi Driver wrote on 20. Aug 2006 at 19:55:



fuel or lubricant?

As I understand it some newer cars use thinner oil to squeeze a few extra MPG out. I guess that means more BHP too. Stirring water uses a whole lot less energy than stirring porridge.

Anyway I've got fully synth 5W30 in my 2.5 -  but I think it's too thin. The handbook says 30 is the minimum oil weight for an Omega, I'm sure the older handbooks used to say 40 though...

My engine sounds more rattley with 5W30 than 10W40.

The fully synth 5W30 is also starting to find it's way out of the cam cover bolt O-ring seals.

So personally I'd say 10W40 semi - which is the majority vote anyway.

NO! ASDA!

im only partial to magnatec because its worked fine in my old 2.0 dohc sierra and zetec fezzy. i hear mobil 1 is also good. so in a nutshell 10w40 semi will do.

any knowledge of this new shell helix oil? is it any good? i swear by shell petrol as its higher octane than most other stations and living here in N.I. i can pop over the border into the south and get more petrol for less money 

omegaV6CD wrote on 20. Aug 2006 at 23:37:


Well if you go for laidback66's failproof maintenance schedule, then it does not matter if you use 30,40, or 50 oil - either way it will not have a chance to reach working temperature before it gets changed!