Any danger with 5w20 syn

[Sasquatch]

I accidentally bought Pennzoil Platinum synthetic 5w20 weight oil instead of 5w30 that I usually use. The problem is that I didn't notice I had the 20 weight until I already poured it in my engine. I was going to drain and refill, but won't if there's no danger running this in the summer. I have 150K miles so I'm a little concerned about the thinner oil. Should I drain it or run it?

[n3985]

VQs prefer thicker weight oil, I would recommend you to change it.

[mydecember1985]

With that many miles, I'd change it. Depending on the car, I've just always known to use 5-30 til 75K-100K-ish, then up it to 10-30 and maybe 10-40 as the car ages. And I have to take into consideration that it's Florida and its friggin hot here

[NismoCefiro]

There is no difference between 5-30 and 10-30. The W is start weight and second number is final warm weight. If you live south like texas, straight 30 will work too. I honestly think ull be fine with one change on 20 considering when you start the car its 5-10 depending on the winter weight you chose.

[L0R1DA]

You guys seem to be a tad confused on oil viscosity ratings. The first number is operating temp viscosity, the W stands for winterized, and the number that follows it is the maximum cold viscosity.

So 5w20 and 5w30 are the exact same oil (in terms of viscosity) except for the fact that the w20 won't thicken as much due to cold conditions.

The only problem with running it in your 150k engine during the summer is that it will leak out more readily through worn gasket points and past worn piston rings on startup. Exterior leaks will mostly come from the valve cover gaskets. Definitely do not use this in the winter time.

*EDIT : Also synthetic oil in general will aggravate any developing leaks as compared to conventional petroleum oil because the synthetic molecules are smaller. If you looked at conventional and synthetic under a microscope, the conventional molecules would be more sticky or clumped together randomly whereas the synthetic molecules are thinner and more homogenous. This is also why synthetic oil filters (mobil 1) have much finer space between the filter fibers than a conventional paper filter (fram).

[PulsarGTS]

Originally Posted by L0R1DA

You guys seem to be a tad confused on oil viscosity ratings. The first number is operating temp viscosity, the W stands for winterized, and the number that follows it is the maximum cold viscosity.

So 5w20 and 5w30 are the exact same oil (in terms of viscosity) except for the fact that the w20 won't thicken as much due to cold conditions.

The only problem with running it in your 150k engine during the summer is that it will leak out more readily through worn gasket points and past worn piston rings on startup. Exterior leaks will mostly come from the valve cover gaskets. Definitely do not use this in the winter time.

*EDIT : Also synthetic oil in general will aggravate any developing leaks as compared to conventional petroleum oil because the synthetic molecules are smaller. If you looked at conventional and synthetic under a microscope, the conventional molecules would be more sticky or clumped together randomly whereas the synthetic molecules are thinner and more homogenous. This is also why synthetic oil filters (mobil 1) have much finer space between the filter fibers than a conventional paper filter (fram).

X2. fwiw, my engine has 130K on it and I switched to 10-30 just to see if it would clear up some minor oil leaks. Its did and the car idled smoother as well. It just seemed a lot more happy. I switched back to 5w30 just to see if it was all in my mind. Nope rougher idle and the dripps are back. I also burned less of the 10w30.

[pmohr]

Originally Posted by L0R1DA

You guys seem to be a tad confused on oil viscosity ratings.

I agree, there is confusion here. However...

Originally Posted by L0R1DA

The first number is operating temp viscosity, the W stands for winterized, and the number that follows it is the maximum cold viscosity.

The second number is the weight at operating temp, not the first.

Wikipedia:

Originally Posted by http://en.wikipedia.org/wiki/Motor_oil#Multi-grade

The SAE designation for multi-grade oils includes two grade numbers; for example, 10W-30 designates a common multi-grade oil. Historically, the first number associated with the W (again 'W' is for Winter, not Weight) is not rated at any single temperature. The "10W" means that this oil can be pumped by your engine as well as a single-grade SAE 10 oil can be pumped. "5W" can be pumped at a lower temperature than "10W" and "0W" can be pumped at a lower temperature than "5W". The second number, 30, means that the viscosity of this multi-grade oil at 100 °C (212 °F) operating temperature corresponds to the viscosity of a single-grade 30 oil at same temperature. The governing SAE standard is called SAE J300. This "classic" method of defining the "W" rating has since been replaced with a more technical test where a "cold crank simulator" is used at increasingly lowered temperatures. A 0W oil is tested at −35 °C (−31 °F), a 5W at −30 °C (−22 °F) and a 10W is tested at −25 °C (−13 °F). The real-world ability of an oil to crank in the cold is diminished soon after it is put into service. The motor oil grade and viscosity to be used in a given vehicle is specified by the manufacturer of the vehicle (although some modern European cars now have no viscosity requirement), but can vary from country to country when climatic or fuel efficiency constraints come into play.

HowStuffWorks:

Originally Posted by http://auto.howstuffworks.com/fuel-efficiency/fuel-consumption/question1641.htm

Multi-weight oils (such as 10W-30) are a new invention made possible by adding polymers to oil. The polymers allow the oil to have different weights at different temperatures. The first number indicates the viscosity of the oil at a cold temperature, while the second number indicates the viscosity at operating temperature.

CarBibles:

Originally Posted by http://www.carbibles.com/engineoil_bible.html

There's more detail on this later in the page under both viscosity, and SAE ratings. But as a quick primer - the number before the 'W' is the viscosity of the oil when it is cold, and the number after the 'W' is the viscosity when it is hot. So a 5W40 oil is one which has a viscosity of 5 when cold, and 40 when hot. The lower the 'winter' number (hence the 'W'), the easier the engine will turn over when starting in cold climates.

...etc. Just figured I'd post some actual facts

[Sasquatch]

Thanks everyone for the helpful responses.

Although I'm in MN, we do get pretty hot in the summer (80 and 90s). I have used synthetic 5w30 since I bought the car four years ago with 40K miles. It doesn't leak a drop of oil and doesn't burn any noticeable amount between oil changes either. Since I want to keep it that way, I'll err on the side of caution and change it out before I drive it. I'll probably go with a 10w40, for the rest the summer at least.

Thanks again.

[NismoCefiro]

Originally Posted by L0R1DA

Also synthetic oil in general will aggravate any developing leaks as compared to conventional petroleum oil because the synthetic molecules are smaller. If you looked at conventional and synthetic under a microscope, the conventional molecules would be more sticky or clumped together randomly whereas the synthetic molecules are thinner and more homogenous.

Synthetic wont aggravate seals, it just leaks by them because of its consistency. It resist clumping and charges in the molecule resist bonding making synthetic last longer. You buy synthetic so it doesnt clump up and cause sludge. What aggravates seals is acidic property of burnt oil since oil before heating up is a base. Longer you wait to change oil, more acidic it becomes and eats at seals and metals.

[eluther3]

While we're talking about oil, I bought my car six months ago with 115K miles. Changed to Mobil 1 5-30, but was wondering if I should consider an additive to clean out the engine, since I don't know it's history. Any thoughts?

[NismoCefiro]

I wouldnt recommend any additives. For the most part the do more harm than good. Its best just to condition your oil changes. I would flush out all fluids. At 115k, who knows when the last time they changed everything. Only additive I use on any part of the car is water wetter. I use 50% coolant, 50% distilled water and water wetter. Otherwise no additives.

[folkz]

Hi to all!

There is no difference between 5-30 and 10-30.
The W is start weight and second number is final warm weight.
If you live south like texas, straight 30 will work too.
I honestly think ull be fine with one change on 20 considering when you start the car its 5-10 depending on the winter weight you chose.

Thank's!...

[talkinghorse]

Originally Posted by Sasquatch

I accidentally bought Pennzoil Platinum synthetic 5w20 weight oil instead of 5w30 that I usually use. The problem is that I didn't notice I had the 20 weight until I already poured it in my engine. I was going to drain and refill, but won't if there's no danger running this in the summer. I have 150K miles so I'm a little concerned about the thinner oil. Should I drain it or run it?

If you have not done so already, change it. 5w-20 will not provide the same film thickness/protection as an Xw-30 under normal operating temps. While some newer engines by Honda, Ford and others specify 5w-20, those engines are designed to operate on the lighter oil...Nissan makes no such recommendations.

[talkinghorse]

Originally Posted by folkz

Hi to all!

There is no difference between 5-30 and 10-30.
The W is start weight and second number is final warm weight.
If you live south like texas, straight 30 will work too.
I honestly think ull be fine with one change on 20 considering when you start the car its 5-10 depending on the winter weight you chose.

Thank's!...

As others have posted, the W rating is the winter rating...any oil at zero degrees is thicker than oil at the upper test limit of 100 deg C (212 F)....its not the same scale. The difference between a 5w-30 and a 10w-30 is that the 5w oil will have better flow characteristics in colder temps than the 10w-XX oil will. The concern with a 5w-20 versus 5w-30 is that the 20 wgt oil will not provide the same film thickness as a 30 wgt oil will at normal operating temps...if the film thickness is not sufficient to prevent metal to metal contact, engine wear will result.

[eluther3]

Originally Posted by NismoCefiro

I wouldnt recommend any additives. For the most part the do more harm than good. Its best just to condition your oil changes. I would flush out all fluids. At 115k, who knows when the last time they changed everything. Only additive I use on any part of the car is water wetter. I use 50% coolant, 50% distilled water and water wetter. Otherwise no additives.

Thanks Nismo. I've already replaced the oil twice, and the transmission fluid looks brand new (my mechanic verified).

Hadn't thougth about a cooler additive. What benefit do you get. It's around 100 degrees here, so I'd be interested in anything that helps the AC cool the car quicker.

[pmohr]

Originally Posted by eluther3

Thanks Nismo. I've already replaced the oil twice, and the transmission fluid looks brand new (my mechanic verified).

Hadn't thougth about a cooler additive. What benefit do you get. It's around 100 degrees here, so I'd be interested in anything that helps the AC cool the car quicker.

Water wetter and others won't make the AC cool the car quicker, it keeps the coolant cooler.

Originally Posted by http://www.redlineoil.com/products_coolant.asp

WaterWetter® is a unique wetting agent for cooling systems which reduces coolant temperatures by as much as 30ºF. This liquid product can be used to provide rust and corrosion protection in plain water for racing engines, which provides much better heat transfer properties than glycol-based antifreeze. Or it can be added to new or used antifreeze to improve the heat transfer of ethylene and propylene glycol systems. Designed for modern aluminum, cast iron, copper, brass and bronze systems.

· Doubles the wetting ability of water
· Improves heat transfer
· Reduces cylinder head temperatures
· May allow more spark advance for increased torque
· Reduces rust, corrosion and electrolysis of all metals
· Provides long term corrosion protection
· Cleans and lubricates water pump seals
· Prevents foaming
· Reduces cavitation corrosion
· Complexes with hard water to reduce scale