hypervish

Have any of you tried a 0W-20 or 5W-20? I've seen the chart below, posted a few times over at Bob Is OIl Guy and am wondering if it's legit. Is the RX300 really back-speced for it?

thomas1

I used 0-30 Castrol Oil like Lex Mex has and it worked great in my RX300.....I dont see any reason not to use the 0-20 and see if your fuel economy improves....

JohnLX300

iTrader: (2)

I'm using 0w20 in my '08 IS250 now, I notice a big difference between 0w20 and 0w30 I was previously using. Car has more power, it definitely feels like it takes less work for the engine to get the car moving. I did see an increase in my avg. MPG's. I went from about 330 - 340 till the gas light came on to 390 - 400 miles to a tank now. For me definitely worth it!

hypervish

I'm wondering if it's too thin for the 1MZ-FE though. I've ran 0W-30 but that's really no different from a 5 weight, the only difference is at startup and then the 0W becomes a 5W anyways.

01rxwhite

Look at the chart, I interpret the three dots and representing the three different RX's at the top of the chart. The RX 300 is the RED dot, the 330 is the BLUE dot, and the 350 is the GREEN dot. Thus, it does say the 300 CAN run with 5-20w or 5-30w. I've run the 0-30w in winter, but mostly run the 5-30w. I have an 04 Acura 3.5 6cyl that requires the 5-20w. My thinking about the 30w vs the 20w would center on the heat in the geographic region the RX300 would be running in? I'd likely run the 5-20w in the winter, then the 5-30w in the summer months. Anyway, the chart looks like a range for the different year models or RX. What do you guys think?

artbuc

Don't think so. I interpret the chart as showing all 3 RX models in the same group. If one of the RX models needed a different spec it would be in a different column. Look at the GS group which has 5 models. Really no connection between number/color of dots and particular model in the header.

hypervish

X2. All of the RX's are in one column.

artbuc

Over on BITOG, someone is questioning the authenticity of this chart. Looks authentic to me.

Lexmex

I've seen a similar chart before, might have been from Europe, but also remember reading about 1MZFE motors and using a W20. I remember seeing this when hearing about W20 and the 2UZFE 4.7L V8 in our 2006 4Runner. I have run W30 and W20 in that vehicle and can run it out to 10K, but the vehicle still has just over 50K miles on it, still young.

I'd still run a 5W30 or 0W30 (like Castrol Syntec).

If I were going to try a 0W20 or 5W20 I'd look at Amsoil, Redline or Royal Purple, very good in my opinion on those weights. Even Mobil 1 does a very good job here, too.

However, I'd keep an eye on the mileage.

RamAirRckt

Talked to a friend who has worked for Lexus since 1989 and he hasn't heard of this document. I have him digging to find any authenticity on it. I am curious....

I did switch to 5W20, and have seen some mpg improvement. I can't complain so far.

hypervish

Let us know what he says. I still haven't tried the 20 weight yet. lol

RamAirRckt

This is what he says, but I send him the document to look at and see if he can figure out the authenticity of it

hypervish

His 98' ES doesn't have VVT-I though which is what I'm worried about. I feel that a 20 weight may be too thin for that mechanism to work properly from what I've read. But, I'm not an expert by an means so I'm not sure if my theory holds true.

Hopefully he can put an end to the debate of whether or not this is authentic.

RamAirRckt

My GS400 does and it works perfectly fine. My mpg did bump up an average of 1.5-2, I have to calculate it to be sure, but so far it as been noticeable over the last 3000 miles, never once getting down to 5W30 mpg levels.

I won't go back....

pilot2

I recently purchased a low mileage RX300 and was provided all the prior service records. I noticed Lexus was using GTMO 5W20 for the oil changes. Anyone tried 0W20 --what could be the downside to its use?