0W 20 v 5W 40
 

I just came back from the dealer service shop and saw that they used 5.2L of Lexus 5W 40 oil when they changed my break-in oil.

I live in the Middle East so temperatures get quite high in the summer (around 32 ~ 40 C all summer long). I'm seeing that the car is designed to be used with 0W 20 oil, is the 5W40 fine?

They didn't select that, they just used what they had.

I experience similar temps here and will use 0W20 while it's NA and 0W30 when it's turbocharged, unless I see oil analysis results to suggest another viscosity is better.

Then again, ask an oil question on a forum and you'll get 100 different answers.

I would have to say that is not good. The only way I would go nearly that high in weight would be if I was racing and logging oil temp and it was going well beyond 230 degree f. Even if you live in a desert, your engine will be way hotter that that paultry 115 degree air.temp outside. Your raidiator will go long before your engine oil overheats if your just driving around.

Any change in engine noise with the heavier oil?

I've heard some of the track guys considering a 5w40 and I live in Dubai, so just curious.

I'm considering switching to Redline engine and transmission oil after mu first service - maybe 0w30 for the engine, unsure about the transmission yet.

Edit: source
http://www.ft86club.com/forums/showthread.php?t=7443

Engine noise is more or less the same, the high pitch sound in the higher rev range is more evident tho. Pretty sure the fuel efficiency has gone down though.

Any risk of engine damage with 5w40 for the next 10k? Or should I be changing it right now or in less than 10k?

It wont kill your engine. But it will make it less efficient and wear more at warm up. I would remove it at 6-7k miles. I dont see a huge crisis at hand but I would make sure you go back to 0-20 (or 0-30 for track)

Direct from the owners manual:

Oil grade: ILSAC multigrade engine oil
Recommended viscosity: SAE 0W-20
SAE 0W-20 is the best choice for
good fuel economy and good
starting in cold weather.

Oil capacity
(Drain and refill

reference*)
Without filter
With filter
5.5 qt. (5.2 L, 4.6 Imp. qt.)
5.8 qt. (5.5 L, 4.8 Imp. qt.)

6-1. Specifications

6

Vehicle specifications

Oil viscosity (0W-20 is explained here as an example):
• The 0W in 0W-20 indicates the characteristic of the oil which allows
cold startability. Oils with a lower value before the W allow for easier
starting of the engine in cold weather.
• The 20 in 0W-20 indicates the viscosity characteristic of the oil when
the oil is at high temperature.An oil with a higher viscosity (one with a
higher value) may be better suited if the vehicle is operated at high
speeds, or under extreme load conditions.

How to read oil container label:
The ILSAC (International Lubricant Standardization and Approval
Committee) Certification Mark is added to some oil containers to

help you select the oil you should use.

This was discussed in another thread. Using a higher viscosity oil due to high ambient temps or track use is categorically incorrect and is a myth. The car was designed for a 20 weight oil not 30 or 40. If anything should be changed to deal with high ambient temperatures or track use it should be the radiator. The radiator and cooling system deal with heat, the viscosity of the oil is designed around engine clearances. An overly hot 40 weight oil is still not as thin as a 20 weight oil and high ambient temps wont make the oil overly hot anyway. The reason this myth continues is that most cars can deal with an incorrect oil viscosity quite well and problems may not show up or may take years and years to show up and may seem unrelated. 40 weight oil is like honey and 20 is like water. Even if the honey was boiling hot, it would be harder to suck through a straw than ice cold water.

Example: Koenigsegg sells a lot of their cars in the middle east and as such they are designed for high ambient temperatures. They did not change the weight of the oil, they simply put in the biggest radiator that could fit.

Ill bet that your car will be fine until the next oil change but keep in mind I am not an expert and I could be wrong, but I'm pretty sure I'm correct.

Me and My friend used this stuff
5w-50

http://www.bestmotoroils.com/oil-img...-Peak-Life.jpg

and 5w-40

we built a 400rwhp turbo lotus, ran great and never had a break down, ever(unless we turned up the boost experimenting :P but what can you expect! to happen at 550rwhp :suicide:)

0w-20 and 0w-30 is perfectly fine for street applications

in the FA20 i would RECOMMEND using 0W30 if you are hard on the engine on a day-to-day basis during the summer or experience a lot of stop and go traffic,

0w30 or 0w40 for track days, trust me its worth having $100 of oil in the engine protecting it when you thrash it


but during the winter use 0w20, and wait for the car to warm up :D

Exactly. Just because you never had a problem doesn't mean you used the correct oil, it just means cars can handle thicker oil and be ok, you may still have been better with the correct oil. At operating temperature oil viscosity is tightly controlled by the viscosity modifiers and chemical make up of the oil. Even at typical track temps the viscosity of a 20 weight is closer to recommended (normal operating temps) viscosity than a 30 weight. I could be wrong, but I believe a 30 weight is still to thick even at slightly elevated temps. Unless you are near overheating you should use the recommended oil weights.

well on a turbo lotus its better to use a thicker oil
1. cools the turbo better, doesnt burn as quickly
2. 2zz-ge has a MMC wall that has a very low friction surface
3. when boosting a thicker oil is better at preventing blow-by than thinner oils
4. higher oil boil temps/ longer warmups( better at holding temps at correct levels when heated)

but also not saying thicker oil is better, but for that application it was

if you live in texas and do a lot of city driving, i would recommend 0w30

That's what the US owner's manual says. I'd be really interested to know what the OP's manual says. In the US, the EPA's CAFE requirements have an influence on the recommended oil. Many cars in Europe recommend thicker oil than the same engine in the US. Europe has Autobhans, the US has CAFE. For instance, I have a Honda Civic with the R18 engine which specifies 5w20 (0w20 for 2012+) in the US, but in Europe, 0w30 is recommended, a thick ACEA A3 rated 0w30 at that.

:suicide: This is just plain old misinformation.

YOU can run -20 at the track and hard on the streets in the summer but dont tell others that the higher wear resistance of a -30 or -40 is mythical.

The only real reason why 0w20 oils are recommended is for the strict emission and fuel economy requirements of today's cars. that's the ONLY reason. Less oil pumping losses. The additive packages are still pretty terrible for most 0w oils, with a few exceptions out there.

Still, 0w40 and 0w20 are still the same weight at startup. 0w40 just doesn't thin out as much as it warms up. Oil temperatures don't just stay a fixed temp, even when coolant temps are kept low. The oil channels in the block that are cooled by the cooling system can only work so well to cool the oil. High power applications will require a separate oil cooler.

Imagine the amount of energy it takes to pump the oil through the engine. In this day, everyone is finding ways to make every fraction of an MPG... even on the "sports" cars.

The first cars to use the 0w oils were the hybrids. Wonder why? 20 years ago, engines were being measured in .0001" inches. Even today, you can get different "grades" of bearings from most import manufacturers with tolerances as low as this. I highly doubt tolerances have gotten any tighter. They have gotten more consistent. Just food for thought.