350z54

It's starting to get warmer out an hot I was wondering is it okay if I switch to 5w40 mobile 1 instead of 5w30 because I do have a heavy foot an do push my car to its limits when I drive it,
it's hard not to for me... so I know that 90 degree weather pushing it to it's limits is not good on motor so I need oil that will help out a little

I was gonna run motul 300v 5w40 but would like to hear other inputs

dcains

iTrader: (15)

I just filled mine with Mobil 1 0W-40, as I have been for a few years - I waited until the warranty expired before changing from the recommended 5W-30. It's good for any time of year, so no need to change it seasonally. I get lower pressure on cold starts, but it maintains pressure properly on super-hot days, so it's really ideal. I'd recommend using it with the M1-110 filter, which is a bit larger than the M1-108.

MicVelo

^^^ This.

I run Mobil 1 0W-40 in my Zs (when I had multiple). I run Motul 8100 E-Tech 0W-40 in my Benz (it's approved for use in AMG engines by MBZ as well as the usual Mobil 1 and others). I was convinced of its goodness through test results I've seen, so wouldn't hesitate to run that in my Zs

rancor

The engine is designed for a 5W-30 and mobil 1 0W-40 is a thin 40 weight. It's still thicker than a 30 weight though so a good choice for a little added protection without going well outside what the engine was meant for.

350z54

Thanks For The Reply i might give 0w40 a go than

MicVelo

That's true but where me and dcains live, very little chance of us ever getting hot or cold enough to thicken or thin to either extreme of the weight range. So temperate here, could probably get away with straight weight.

Ain't gonna try though...

venture210

10w-40 amsoil signature. I have slightly looser clearances in my bottom end though. Still within OEM specs 0.0020 mains 0.0022 rods

terrasmak

iTrader: (8)

Well 90 degrees out side is not hot, and you are not pushing your car hard at all. I run an xw40 for my car. Summer temps are 115 and car is tracked(not talking about silly little drag passes ) in that temp.

Swaglife81

5W oil is all weather oil to be on the safe side for the factory. It's a safe weight for a car that might end up in Canada at 0 degree weather or the Bahamas in 100 degree weather. It's not the perfect summer oil or the perfect winter oil.

5W 20 for gas mileage all climates
5W 30 more of the factory all climate normal but 1 mpg less than 5w20
5W40 for higher mileage cars in all climates

10W30 is prime summer performance oil without a doubt in any car made after like 1999
10W40 again prime summer performance but for higher mileage cars, mileage varies

0W30 for winter/higher elevation/cold weather

My Cobra and Vette buddies in the 500-650 RWHP range all run 10W30 when it's 70+ degree season.

Anyone saying an engine is designed for 5W30 is an idiot. The climate, mileage, ambient temps, and the use of the car determines what oil weight should be ran. A manufacturer has to be safe. They can't list 20 different oil and oil types for a car. They can't tell someone run 0w30 in cold weather if that owner moves south and runs the same oil in 99 degree weather and so on. Same for 10W30 in cold weather, it's to thick for cold weather. I hope the numb skills who think a car has to run a certain weight at all times reads this and does some research.

rancor

Let's start off for the designed for 5W30. Apologies the more correct statement would be the nissan decided the engin operates optimally in NA environments and driving conditions on a 30 weight at operating temp in temperatures likely up to 100 or 110F. At some temperature it would likely be acceptable to switch to a 40 weight. If you are running the engin well outside of normal conditions like tracking you may need additional cooling and a higher weight oil to keep the thickness acceptable and the oil presure up.

As for the winter modifier . You want to give me a reason why 10W30 is better in the summer? It's more like 10W30 is acceptable in the summer not beneficial. I don't see any reason not to continue run a 5W30 or even 0W30 in hot ambient temps (not including price). They are all going to be very similar thickness at startup and the same at operating temp. If you going to get into the small differences at operating temp the winter wight will not be directly related to the operating (100C) thickness and will change from manufacturer to manufacturer. For example at 100C Kinematic Viscosity @ 100ēC, cSt (ASTM D445) for mobil 1 10W30 is 10.1 while amsoil signature 0W30 is 10.5.

Also looking at the new mobil 1 0W40 FS they dropped the operating thickness down to 12.9 cSt so it is so close to being a 30 weight (9.5-12.49) I don't think it could ever cause issues in environments(temp ranges) where a 30 weight was recommended but I wouldn't really want to run it in a environment recommending a 40 weight.

dkmura

iTrader: (64)

Just a few comments on this thread. First, if you haven't at least perused the UOA thread for VQs, you are missing one of the highlights of this site. Resolute did a fine job of posting a database of UOAs for everyone to read and learn from. Here's a link:

https://my350z.com/forum/engine-and-...d-info-60.html

One of the more highly ranked oils in that thread, Mobil 1 0-40W has been superceded by a new formulation starting in 2016 called 'M1 0-40W FS'. It's showing up on the shelves of auto parts stores in Denver, CO and is usually on sale at various times throughout the year. With impressive specs, this new 'FS' formulation is now my choice for both racing or street driving, with either the DE (street) or HR (race) engines.