GXS

Hi, I'd like to know what oil viscosity to use on a '99 RX 300 with about 30K miles and 5 1/2 years old. The weather is always warm/hot with rain sometimes. Avg. max speed is about 40 Mph. Also I've never used synthetic oil, is it OK to switch to synthetic oil at this mileage?
Also what are the recommended oil change intervals?
Also, in the FAQ there are 2 oil filters mentioned. Can I buy them at a Toyota dealer?
Oh and the car feels slow now and there is some engine nocking. Will a bottle of Chevron Techron help?
Thanks.

Fern

My '99 had 50k miles on it when I bought it.

After removing the oil filler cap I noticed traces of varnish buildup. Bought a bottle of valve/ sludge and varnish cleaner, put in the crankcase and ran car for 1000 miles and then changed oil and filter myself.

This was my way of flushing old stuff out.

Now I run Castrol semi-synthetic 5w30 and use it all year round with new oil filter changes every 3100 miles. Since running the semi synthetic and doing the engine flush, even the dipstick seams cleaner.

My oil filler cap says to use 5w30 and as for the oil filter. If your vin number indicates car to be of Japanese decent, use the made in Japan filter.

Its your choice to run "full" synthetic, you might want to do engine flush first though.

Keep in mind if running full synthetic that the owners manual indicates that "the use of synthetic oil does not extend the oil change intervals."

Good luck and happy motoring with the RX.

Cheers,

Fern

LexRX

I agree with Fern - do an engine flush before using synthetic, go with the manual-specified weight (5w-30) and change the oil under the same intervals as you did before.

The origin of any RX300 will be Japan.

mooretorque

5W-30, Mobil-1, same intervals.

Wow, 30K on a '99! I considered ours low mileage with less than 60k!!

Lexmexico

I live at a 7,700 foot level here in Mexico City. 25% less oxygen than sea level. Have had my 99 RX300 AWD here since 43,000 miles, now at 70K. I use Mobil 1 15W-50. The motor was burning 5W-30 and 10W-30 too much, but no such problems with 15W-50.

I use a Chevron product here called Progard, which includes Techron (Pemex is the only gas here, and poor quality at that) and it has really cleaned the system.

I have also used a product called Restore, which goes where the oil goes. This really cleaned up the engine, and the motor performed much better and quicker afterwards.

I would not recommend 15W-50 for sea level, either 5W-30 or 10W-30 will do you well.

I personally use a K&N oil filter. However, if you are going to go with one of the Toyota filters, go with the one from Japan, much better filter element. Have also had a good experience with Mobil 1 fitlers, but I personally recommend the K&N filter. Despite the heavier weight oil, my car still feels like I have 5W-30 in it when I have the K&N in.

My oil interval here is about 3,000 miles. I know some friends with other Lexuses here and they have seen oil burn beyond 5,000 on a synthetic with 5W-30 or 10W-30.

At a cold climate, you must go with 5W-30. Do not even think about the 0W-40 provided by Mobil 1. That would leak too much. If you are worried about leaks when you switch to synthetic, go with 10W-30 first.

GXS

Thanks everyone for your replies. I'll definately "flush" the engine first before switching to synthetic. I'll be going with Mobil 1 5W30.
Thanks again.