Hi to this board from a new member

I've quite recently purchased a GS 300 Mk II, with LPG conversion, and a full Lexus Service History upto 131000 miles, and am looking at doing most of the servicing and maintenance myself - will probably keep car for a good while - hence resale value not of importance.

Having access to the Mitchell On Demand Service & Repair Manuals, I checked which Engine Oils they would recommend for the car.

Back came the answer 5W-30 or 10W-30. Reading through most of the discussions, people recommend using Mobil 1 (of which I recently bought 2 cans), but this is 0W-40.

So the following questions beckon:
1) Would it be wise/safe to use Mobil 1 on such a high mileage car
2) What formulation/brand do the Lexus dealers use
3) Does anyone know of any good sources for 5W-30 or 10W-30 oil, Don't mind buying in 25 litre containers
4) Is there another oil you would recommend?

Thanks in advance for any responses and answers. If these questions have been asked before, then apologies, but spent over 2 hours looking and searching without any luck.

If the engine is worn then switching to fully synthetic can cause issues. There is no problem with using 0W/40 if offers better protection than a normal 5W mineral oil however I always found Mobil 1 made the engine a bit noisy.

If you don't want to use a fully synthetic oil then Castrol GTX Magnatec is a good semi and available in 5W/30.

Lexus dealers all use different oils so there is no standard.

It really doesn't make too much difference what oil you use as long as it is within the Lexus recommendations and it is changed on time.

Thanks for the that; but what is Lexus' recommendation? ( I wasn't given any manuals with the car )

I would recommend that you stick with Mobil1. Two reasons first with FSH the engine should be perfectly fine and secondly Mobil1 is really great though costs a little more. It is still Oil but fully sync. You wont be putting veg oil or water its not that thin. The engine could sound louder as Colin poits out but you will have to judge this afterwards although using Mobil11 will not do any harm on a FSH Lexus. It will improve it. Also with Mobil1 change you can clock up another 20K miles.

On the GS300 most Lexus dealers from my enquiries use either Mobil1 or the Shell fully sync. Its always fully sync with lexus. Although the advice they give is that semi is also perfectly OK since temperatures in UK do not go beyond whatever it happens to be -10 and so on. So they will tell you that semi is perfectly ok and the manual specifies the following:

20W-50
15W-40
10W-30
5W-30

For Mobil1 you will need 6Ltrs with new filter.

Many thanks for the suggestions/info.

I'm still a bit hesitant on using Mobil1, as my last experience of the stuff resulted in over 800 quids worth of engine damage to an Audi 90 Quattro I used to have 10 years back.

Saying that, not too sure whether this is a good price, but bought 2 x 4 litre Mobil1 from CostCo - 19.99 ex VAT (23.49 inc)

Was the 8 litres for £23.49?

Normally over 3x that price in Halfords etc.

I have always and always will use 76R 10w-30... very expensive, but superb results.