FAQ'S

In simple terms, the first part of the viscosity designation (W grade) is an indication of the product's ability to help an engine crank and start, and for the engine to pump the lubricant.  The lower the number (0W is the lowest), the lower the temperature at which the product can be used.  So the W greade is related to the lowest temp your engine sees when you start the egine on the coldest morning  of the year.  Keep in mind that a lower W grade pumps and helps an egine to start better than a high W grade.

The second part of the viscosity grade is related to the viscosity your engine sees at operating temperature.  So, a higher number is a higher viscosity grade and provides more viscous oil at operating temps than lower viscosity grade oil.

Because of other factors, such as egine design, fuel economy and power, it's not always safe to assume that a higher viscosity oil is better for your engine.  Always consult your owner's manual for the right oil to use for your particular engine.

The instructions are pretty simple:  You just change the oil as you normally would.  Any "confusion" is just myth.   You can switch from conventional oil to Mobil 1 synthetic oil (and back again, if you want) without following any special procedures.

Motor oil breaks down over time.  When this happens, it loses its effectiveness and no longer properly protect your engine.

Oil should be changed before the breakdown level reaches the point where engine damage can result.  Because it is tough for the individual motorist to determine when the level is dangerous, automobile manufacturers provide recommended oil change intervals.  These recommendations vary by model, year & manufacturer.

It is not likely that you would form a gel by mixing the two oils since they should be compatible with each other.  However, we do not recommend mixing oils as a general practice since oils are complex mixture of additivies and base oils that can be destabilized.  You would be better to run all Mobil 1 synthetic motor oil and run it for longer than mixing it with "regular oil."

ExxonMobil recommends a 5-year maximum shelf life for engine oils, including Mobil 1 synthetic motor oil.

If DEF is stored between the recommended temperatures of 12F and 90F, the expected shelf life is approximately 1 year.

Avoid storing diesel exhaust fluid at high temperatures whenever possible.  When stored in an environment where high temps occur, typically over 90F, this can lead to reduced shelf life and the formation of ammonia in the DEF.

Yes.  DEF will freeze if exposed to temperatures below 12F.  However, DEF that has frozen can still be used once it has thawed and has returned to a completely liquid state.

No.  By comparison to other fluids, such as diesel fuel and brake fluid, DEF is less hazardous, composed of naturally occurring components and is biodegradable.  

DEF is listed as a "non-hazardous" material and can be transported without a DOT approved hazardous substance placard.

It is expected to be approximately 2% of fuel consumption, depending on the vehicle operation, duty cycle, geogrpahy, load ratings, etc.

DEF consumption is directly related to fuel consumption.  A truck averaging 6 MPG can expect to go approximately 300 miles on 1 gallon of DEF.

The dose rate will vary slightly amongst engine manufacturers.  While most engines will have a dose rate of 2% of diesel fuel consumed, the dose rate will range from 1% to 3%.

Vehicles that use DEF will have indicators on the dash that will alert the driver of the quantity of DEF on board.  A gauge similar to a fuel gauge will indicate the level of DEF.  If the vehicle is operated such that one would run completely out of DEF, the vehicle's power will be reduced enough to encourage the operator to refill the DEF tank.  Once the tank has been refilled, the engine will resume normal power levels.

It is actually more important to consider what materials will harm the diesel exhaust fluid itself rather than what materials the DEF can harm.  DEF will not harm most materials, but the metal from aluminum tanks can leach into the DEF causing it to become contaminated.

There are many materials that will damage the DEF, so caution must be used when selecting an appropriate storage material.  DEF-approved stainless steel and poly are common materials used in DEF storage.

Yes.  DEF can leave a chalky residue behind when the liquid evaporates.  This is normal and can be cleaned off with deionized water.

The amount of taxes you pay on fuel depends on what state and county you live in.  As of January 2023, the amount of federal tax, as well as the average total sales tax for gasoline & diesel fuels, is listed below:

• Gasoline:  18.4 cents/gallon
• Diesel:  24.4 cents/gallon

For gas & diesel tax in the United States listed by state, click HERE.

While you may think it's a great idea to keep clicking the nozzle at the gas pump, the reality is that fuel in an overfilled tank can slosh or seep right out.  So when the automatic nozzle clicks off, stop pumping.  The Car Care Council says that overfilled or improperly closed tanks result in vaporization of 147 million gallons of fuel every year.  That means when you stop overfilling your tank and seal it properly, you'll be maximizing fuel efficiency and reducing carbon emissions.

Absolutely.  Over or under-inflated tires can negatively affect your fuel economy, so before your trip, make sure your tires are at the manufacturer's recommend PSI (pounds per square inch).  The recommended tire pressure is usually printed on the inside of your driver's side door.  Some newer models of vehicles even provide pressure monitors that alert you when your tires need inflation attention.

Unless it is stated in your vehicle's owners manual that your car requires Premium gas, you're wasting your money buying the more expensive fuel.  Most vehicles run well on regular, unleaded gasoline, and paying the extra money won't optimize your car's performance.

Ethanol contains less energy per gallon than gasoline.  According to the Energy Information Administration, the energy content of ethanol is about 33% less than pure gasoline.  Most gasoline contains about 10% ethanol, but some higher blends can be problematic for engines and potentially void warranties.  Be sure to check your vehicle's owner's manual before filling up!