Re: you should be fine then
 

I'm not going with royal purple anymore. I heard enough bad stuff to switch back to Mobil 1. I heard that after 3k it starts to thin out. I also heard that it breaks down way before Mobil 1 breaks down. Also the prices are crap. All I'll do is go to Wal-mart and get a 5 quart Jug of Mobil 1 for $20.

synthetics
 

I used Catrol Syntec or Syntec Blend and it seems to do well in my Geo at 7000-8000 mile oil changes adding a quart during that time as well. Mobile 1 has gone down in quality/service life and if your engine calls for 30w and you use 20w then you are running out of lubrication and will wear your engine out really fast on hot days. You are better off with keeping it in longer as long as it is slippery between your fingers and doesn't reak of blowby gasoline and you can still see the dip stick through the oil. If you want to really stop wasting money and are going to keep the car for several years then go crazy like I did and go with Synlube and forget about changing your oil ever again. I am still getting used to the idea that I don't have to get under the car again for 3 years until the 36,000 mile filter change. I hear that Royal Purple is supposed to built up ester deposits in the engine and is not good for street use or was that RedLine???

It doesn't really get that
 

It doesn't really get that hot here. I visited St. Louis in the summer and that was freaking hot. You couldn't even go outside without feeling you're out of breath.

In the summer it's 85-90 degrees here. I'll be changing my oil every 3k, doesn't matter what oil I use. So can I still use 5w-20???

20-30??
 

What the engine recommends is what you should use. The weight of the oil needed is a function of the oil temperature and how much cooling you get from the outside air and the load on the bearing surface that the oil pressure has to support. Too thin an oil and the bearings don't get the hydralic pressure needed to prevent metal to metal contact. Put a belly pan on and block the radiator and the engine temps go up. If you check the owners manual it usually will show you a graph of the heat range and the oil weight needed. The Synlube I have now in my xB is 5w50 and the manual calls for 5w30 but I don't have a problem with the 50 weight as it protects more and in this case doesn't drag the mpg down at all. Changing the oil while it is still good is just a waste of oil and money.

Re: synthetics
 

I think redline's base stock is a polyol ester, not to be confused with the cloth. I'm not sure about RP. I haven't heard about ester deposits before. Polyol esters are the base stock in jet engine oil. It's said to be more resistant to evaporating and extreme heat because their chemical structure has increase stability over conventional base stock, which are simply distilled crude oil.

Here's some Info: https://en.wikipedia.org/wiki/Motor_oil

damn everybody is saying
 

damn everybody is saying stick to heavier oil. Nissan sucks, their engines are designed for heavier oils.

Mobil 1 says the lowest I can go is 5w-30, and that is what everybody else is saying. So if I go to 5w-30 instead of 10w-30 my warm up will be better?

Quote:5W-30 is recommended
 

Even the prius? That bones, the insight is 0w20, :p

Re: damn everybody is saying
 

Not necessarily. Living where you are, it probably never gets below 40-degrees: which is where the 0w comes-in. Some owners manuals recommend a certain grade to use all the time or part of the year. Where the startup really counts is when it's below-zero outside and the car's been sitting outside all night. The thinner oil will pump more quickly to vital parts.

As for the second number, you probably want a higher number, especially if you have a hotter 'stat.

RH77
(KCØWPM)

IMHO, if you are going to
 

IMHO, if you are going to change your oil every 3000 miles and if you are going to stick with a 30 weight oil, don't waste your money on synthetic oil. Not only will you be wasting your money, you will be throwing out perfectly good oil and you will see no FE benefit.

Geez, if you hate you car so much and you keep saying that you are going to get rid of it, why are you putting so much money into it?

Re: IMHO, if you are going to
 

Because I don't know when I'll get rid of it. I've only spent less than $150 to gain 5mpg.
The reason I changed every 3k is because after 3k royal purple starts to thin out. And that is not good when my engine temp sensor is barely working and turning the fans on in the city all the time.