I have a couple fresh quarts of Mobil1 0W30 in my garage. Why? I don't know why I bought it so please don't ask. Anyway, I'm going to do my first oil change today with 1,500 miles on the odometer. Is it okay to use 6 quarts of Mobil1 5W30 and a half quart of the 0W30 ? I figured if I do this for the next few oil changes it will get used up so it wont go to waste. Okay to do or should I just dump the 0W30 at the local recycling center? Thanks!

 

Use it, mixed with the 5W30. It'll be fine. FWIW I do this on purpose in the COLD months here. :cool:

 

You could always take it back to walmart (thats where you bought it right!) and exchange it for the 5w-30.

 

You'll be fine. The other thing you could do is put in one 10-30 and one 0-30.

 

I interchange the following Mobil One products all the time: 0w-30,5w-30,10w-30. Absolutely they are interchangeable! The reason I do it is because at times, the sales dont always offer the exact viscosity that I would have liked. I also use Mobil One in 3 other Toyota Landcruisers.

 

BIG Dave, 0W30 Is mainly for VERY cold weather driving, 0deg and less. IT is also very good in racing where you want good lube and low friction drag in the engine as well. You can mix it as you asked about. I just wouldn't run the stuff all the time in a warm climate as it would give less quality lube than a heavier viscosity oil will(10W30 or 20W40) :smash: :seeya

 

FWIW, Mobil tells me that the 5W-30 and 0W-30 perform identically at all temps between +300'F and -40'F. If you get colder than that, then the 0W- starts to show an advantage.

 

...and you would be right!!! The 30 part is the viscosity at high temps and the 0 is at low...0W30/5W30/10W30 should be interchangeable...any chemists out there with more info??? :seeya :chevy

 

I forgot to mention I read somewhere there is a 1-2% difference in gas mileage between weights 0w-30, 5w-30,10w-30. (roughly .5 mpg) Also if you look at the PDS for Mobil One: the pumpability limt *F are -62*F,-58*F,-49*F respectively.

Also as a practical but unseen consideration you want to use the weight that have used the least or no VI or viscosity improvers which 5w-30 and 10W-30 does.

 

As a chemical engineer, I will answer that you are correct, the 30 number is the ultimate viscosity at temperature, the 0 number is what the oil flows like at lower temperature. It is indeed advantageous to use 0W-30 in most climates rather than the higher viscosity flow oils. You should see an increase in both gas mileage, and you may see an increase in power. These will not be significant, but something is better than nothing.

The primary concern at high temperature is the volatility of the oil, and it's potential for break down. Most of the synthetics perform quite well at elavated temperatures, with very low volatility.

I have been running Amsoil 0W-30 in all of my vehicles, regardless of season. In my daily driver, I have seen an increase in gas mileage of nearly 2 miles/gallon. I chose the Amsoil due to it's superior performance in the volatility testing compared to other synthetics, along with the fact that it is tested to all of the relevant API and GM standards. :cheers:

 

I have been using Amsoil for about 12 years now. I have tried just about every viscosity they sell. I found that the 0W30 gave a slightly less overall operating oil pressure reading than the 10W30- 5W30.Nothing to be concerned about.
Any of the three 30 weight oils work well in summer operating conditions.
A lot of people overlook the most important aspect of lubrication and if you read about it or do reasearch, you will find out that most or all of the engine wear happens when you START your engine. Not when it is hot and at full operating temperature. A thinner 0W30 or 5W30 will flow more quickly and lubricate your vital engine parts more quickly when you fire up your engine.Therfore the 0W30 may offer more ACTUAL protection.
I had an experience once when drag racing where the oil filter seal blew out and the engine lost ALL it's oil, before we knew it the oil went all over the tires and the engine was turning 5000 RPM this was at 100 MPH the oil pressure gauge read 0 PSI. Hit the key and turned the engine off. Then replaced the filter and added 5 (yes 5 quarts, count 'em) Fired the engine back up and ran it for a few more years, then opened and inspected it, NO signs of damage after. I never doubted the protection Amsoil provides and do not use anything else after seeing how well it worked during that mishap. Usually use 5W30 or 10W30 but thinking of using 0W30 again. Yes it is at start up where most of the wear happens not when you are cruising down the hi-way doing 80 MPH in 100 degree weather.