Which weight of oil should I use?

302MuchForYou · 09-06-2002

I've got a '91 5.0 LX with about 160k on it, and I'm using 10w40 in it right now. Should I use a 20-50 or should I stick to 1040?

Thanks...

Ron · 09-06-2002

Are you burning any Oil? What type are you using?

Vortex · 09-07-2002

In NE with that many miles.. 20w50...
Id also recommend a bottle of Lucas oil treatment to help around the rings...

302MuchForYou · 09-07-2002

I'm using Castrol GTX 1040, and yes it burns a little oil...

kchronister · 09-09-2002

So what's the cutoff... Mileage wise? Start hitting the 20/50 around 100K? If you notice burn rate of X quarts per X miles?

What would the board rec for me: 95 GT with 80,000 on it, not burning significant oil (i.e. not enough to notice between 3,000 mile changes)

Vortex · 09-09-2002

when I worked in parts i always recommended 20w50 to customers with 75K and up. if the engine has been hard, sometimes the thicker oil is better and protecting the bearings and sealing leaks..