Engine Oil: what's best?

[BergDonk]

We all love an oil thread!

Years ago I got a Mazda rotary rebuilt that I'd previously been running Castrol in exclusively. When I collected the motor, the rebuilders specifically said something like "If you continue to use Castrol in this engine then the warranty is void" I asked how he knew I'd been running Castrol, and he said the evidence was inside when they stripped it down, sludge and wear. Many years ago, and no doubt numerous new formulations, but you remember these things.

I've been using Mobil 1 5/50 in my VRX @ 15k intervals since 20k, and just did the 195k service. No oil consumption, and no smoke, and no oil issues yet. Its a country car, so limited stop start, and rarely does less than 20 kms once started. Also switched the kids TJs to the same upon purchase at 110k and now at 160k with changes at 10k as they are more a town car. Dunno what they'd had in them before I got them.

Until I get 4-500k up I won't really know whether the M1 was a good choice or not, but so far, so good.

Steve

[Madmagna]

We all love an oil thread!

Years ago I got a Mazda rotary rebuilt that I'd previously been running Castrol in exclusively. When I collected the motor, the rebuilders specifically said something like "If you continue to use Castrol in this engine then the warranty is void" I asked how he knew I'd been running Castrol, and he said the evidence was inside when they stripped it down, sludge and wear. Many years ago, and no doubt numerous new formulations, but you remember these things.

I've been using Mobil 1 5/50 in my VRX @ 15k intervals since 20k, and just did the 195k service. No oil consumption, and no smoke, and no oil issues yet. Its a country car, so limited stop start, and rarely does less than 20 kms once started. Also switched the kids TJs to the same upon purchase at 110k and now at 160k with changes at 10k as they are more a town car. Dunno what they'd had in them before I got them.

Until I get 4-500k up I won't really know whether the M1 was a good choice or not, but so far, so good.

Steve

Funny you mention the Rotary, in my past life I used to work exclusivly on Rotaries, I had the same policy, only my policy was for Penrite oils only. IF a customer used Penrite I gave a 3 year unlimited KM warranty, if Shell or Castrol was used warranty was void. Especially Castrol back then used to have a very bad reaction to the oil control ring "o" rings, they would go hard and cause what we would see as being similar to valve stem seal smoke. Also there would be a lot of glazing on the end housings as well.