Quote:
Originally Posted by TheSpoils
I'm sure this issue has come up already, but I am too lazy to find it.
My dealer said I should change the synthetic 0w-20 every 4500 miles. Honestly, I have not reviewed the manual but that seems too soon. As a matter of numbers lets estimate that standard Nissan Altima 2.5L engine can provide an average of 30mpg combined highway + city http://www.fueleconomy.gov/feg/FEG20...neVehicles.pdf, on the NAH we are averaging say 40 mpg. My assumption is that, the 25% better fuel economy is due to the electric motors of the hybrid system. During the driving time that the ice is not "on" I will assume that the oil is not being deteriorated. So if I have driven a total of 4,000 miles, the ice has only been operating for about 3,000 miles, the other 1,000 miles came from the electric motors. My theory is that the actual miles driven are not the actual miles on the ice, so the oil change frequency should be adjusted for such. Any one of you math geniuses out there can please review my theory and my math.  |
I don't think any of your assumptions are particularly good. Also, the maintenance guide (looking at the PDF right now) basically gives 3750 or 7500 mile oil change intervals depending on whether you're following premium, schedule 1 or schedule 2 intervals.
The Cartalk guys suggest oil changes every 5K miles (every 3K is too often and excessive) now per the URLs below:
http://cars.cartalk.com/content/advice/oilchanges.html
http://www.cartalk.com/content/colum...vember/12.html http://www.cartalk.com/content/colum.../March/01.html
http://www.cartalk.com/content/colum.../April/01.html
The 1st URL and
http://www.cartalk.com/content/colum...August/05.html talks about what happens to oil in general and how it picks up water and other contaminants.
FWIW, my 06 Prius' schedule dictates 5000 mile oil changes regardless of habits and conditions. Perhaps Toyota is trying to head off the posibility of oil sludging like they experienced on a large # of V6 engines over a wide range of years.
Also, per
http://www.fueleconomy.gov/feg/sbs.htm and the MY 08+ test procedure, non-hybrid 08 Altima w/CVT rates at 26 mpg combined and the NAH rates at 34 mpg combined. Another thing of note, I'd imagine the Nissan detuned the 2.5L 4 to produce less power (158 hp vs. 170 or 175), presumably to partly help w/mileage and fuel economy, so that's got to be responsible for some of the mileage improvement.
Also, the CVT in the NAH I'm sure is TOTALLY different from the one in the non-hybrids.