RX350 5w20 vs 5w30?

[Scottydog]

My wife's 09 RX350 manual and the oil filler cap specifically states 5w30. The dealer recommends 5w20, pointing to a tsb allowing it's use. The tsb says use the viscosity recommended in the manual in one paragraph, and then goes on to recommend 5w20?

Does it make a difference? I've been using PP 5w30/wix filters.

TSB:
Toyota Motor Corporation manufacturing plants have begun using ILSAC GF–4 engine oil. This engine oil is recommended due to its superiority in terms of fuel economy and engine protection and due to its benefits for both the customer and the environment.

ILSAC GF–4 can be used in all Lexus engines.

NOTE: The recommended viscosity grade for this oil differs according to vehicle model. Use the recommended grade specified on the oil filler cap or in the Repair Manual or Owner’s Manual for each vehicle.

Applicable 2006 model year Lexus vehicles.

Vehicles
Recommended ILSAC GF–4 SAE 5W–20 Engine Oils

This oil has been set as the Lexus genuine engine oil, starting in February 2006 for the U.S. This (5w-20)oil is superior in terms of fuel economy, engine protection, and cold
starting performance.

 

[bepperb]

All the Toyota 5-20 TSB's are very confusing.

It really won't matter which you choose, assuming it doesn't stay above 100 or below 0 where you are much.

 

[PhoenixTL]

I Have a 2001 RX and use 5W-30 oil...some folks have gone to 0W-30 German Castrol...

I dont think I would use 20 wt in those engines.,...

Check out www.clublexus.com for more info

 

[mechtech2]

Nice and tight answer from bepperb.
They are very similar - use either.
But don't be afraid of the 5-20 - you will gain a bit of pep and economy.

 

[bepperb]

Phoenix,

Your engine is completely different. In fact, you're two generations of engine away. The 3.0 and the 3.3 and the 3.5 are all very different from one another.

 

[Scottydog]

Thanks for the input guys. I live in sunny California, so temps are not extreme either way.

What would you guys run in this engine?

Pennzoil $15 rebate form:

http://pennzoil.com/documents/04946 PZ online form.pdf

 

[Eddie]

I would continue to run 5w30. Many many millions of miles with that engine on 5w30 proves it works, I doubt you will be able to measure any fuel mileage differences. Unless you race your vehicle against a clock you probably will not find any more power.

 

[Scottydog]

My wife is not taking the RX to the track! lol

I agree I'll likely stick with 5w30. As the saying goes, the biggest enemy of good enough is "perfect".

 

[bepperb]

It would depend on what my other needs were. It's probably easier to have 5-30 on hand since it runs in just about anything.