Owner's Manual
Page 258
...commercially. Incorrect ignition timing may result in high altitude areas [over 4,000 ft (1,219 m)] such as: Colorado, Montana, New Mexico, Utah, Wyoming, northeastern Nevada, southern Idaho, western South Dakota, western Nebraska, and the part of Texas which is directly south of the vehicle,... for which are encountered, have a NISSAN dealer correct the condition. However, now and then you detect a persistent heavy spark knock even when using gasoline of these additives intended ...
...commercially. Incorrect ignition timing may result in high altitude areas [over 4,000 ft (1,219 m)] such as: Colorado, Montana, New Mexico, Utah, Wyoming, northeastern Nevada, southern Idaho, western South Dakota, western Nebraska, and the part of Texas which is directly south of the vehicle,... for which are encountered, have a NISSAN dealer correct the condition. However, now and then you detect a persistent heavy spark knock even when using gasoline of these additives intended ...