I have put Regular (87) in mine since the day I bought it and it runs fine. What are others using and is there a specific reason if using higher then 87? (such as modifications that were installed that have warranted the upgrade)

generally, i put regular in. i think i put premium in once...

~mike

Always Premium 92+ Chevron....... Triffid

around town I use 87 but on trips I use the best they have. 90+

there is a huge difference in performance when switching from 87 to 93 and back.

i use 93 on road trips and 87 when my wife uses it as her soccer mom vehicle.

you also get better gas milage using 93.

I use 87/89 normally at low altitude. If i'm going to drive at higher altitudes, i use 93. It makes a huge difference driving to places like Yosemite, or anywhere over 3 or 4000 ' elevation. So generally when i *leave* the bay area, i upgrade gas.

Also i tend to do one tak of premium chevron or shell gas every 4 or 5 tanks. Cant be doing that much wrong becuase i have 263K miles on my 1991 truck now...

93

It just runs better.

93

Runs better and gas mileage is improved for myself.

The 4.0L that is in the Pathfinder is a Dual over head cam engine. meaning that it has 24 valves, also meaning that there is more air and gas comming in and out of that engine as opposed to the standard push rod or SOHC engines. Therefore Nissan and anyone who knows a thing or two about engines and fuel will tell you that 93 octane is best for your engine. It reduces pinging and detonation in older engines, and mixes better with the larger quantity of air that is being pulled in by the DOHC. On top of that 93 octane reduces the amount of carbon build up on your internal components due to the higher temps on the detonation stroke. Your engine will run cleaner and longer by using 93 octane. Some more added benifits to running 93 are that you will have better performace, better gas milage, and less maintenance due to not following your owners manual. You may not think you are hurting your car by using sub-par octane levels, and saving some cash at the pump but in the long run you will pay for it in the form of maintenance bills

so to answer your question I ALWAYS use premium gasoline in all of my vehicles. DOHC or not it's still better for your car.

Simple as this: on regular and mid-grade I hear knocking, on Premium I don't. So when we can afford it, such as now, we run premium. When gas goes back up to 3.50 to 4.50/gal we will (regrettably) have to switch to cheaper grades and hope we don't bust a valve from detonation.