My hubby and I own a 2000 Nissan Maxima with 120,000 miles on it that we bought new. It has received all the recommended maintenance. The owners manual recommended using premium gas but due to high gas prices (and my husbands dislike of unnecessarily parting with any dollar) we have occasionally run the car on mid range (89-91 Octane). Now when we run the car in the summer with the air conditioning on, not only is there a tremendous amount of valve clatter but the mileage drops from 28 mpg to 15 mpg. My hubby says this is from running the AC and so I am no longer allowed to use it. I think that it is either from stiffing the car on octane occasionally or the car is broken. What do you think? All I know is I am tired of driving without the AC. Sign me, tired of sweating in the Midwest, Melissa Prete
If the manufacturer recommends a higher octane fuel, then this is what you should be using the maintain and optimal running condition.
As for the a/c, you may want to have it looked at. It's possible that it's over-working for some reason and this could be putting a strain on the engine.
I know that in the summer I use a higher octane fuel because I use my a/c, but my vehicle is 20 years old. Higher octane fuels help maintain proper detonation.
I would have the vehicle looked at by a technician. You may have a timing or idle issue that is causing problems when you turn on the a/c.
If there is a problem with the vehicle, it's there whether you are using the a/c or not. The a/c is just making it more noticeable, so I would suggest having it looked at.
〉 Answered on Jun 27th, 2008 by Lori Johnson, Owner and Instructor at Ladies Start Your Engines