Manager Forum

We have a customer with a '06 Maxima with a 3.5 engine who was told by the dealer to use only premium fuel in her vehicle. Is this truely recommended & if so, does anyone know why?

Mine says premium unleaded on the gauge and fuel door.

We've even heard that for the newer Sentras!!!!!!!!!!!!!!!

Yes, 91 octane for that engine.

Higher octane fuels are more resistant to igniting by compression rather than the spark, which allows manufacturers to increase the compression of their engines. A fuel mixture ignited by compression is called knock. Knock is bad. What occurs is the flame front of the compression induced explosion runs into the flame front of the spark induced explosion. Bang! This can cause internal damage to the engine. Sometimes it's barely audible outside the engine but inside...woo-boy!

If it says 91, use 91.

John C. wrote:We've even heard that for the newer Sentras!!!!!!!!!!!!!!!

I just looked...wow! The SE-R SPEC V model Sentra take 91!! Holy cow!!

ricmorin wrote:Yes, 91 octane for that engine.

Higher octane fuels are more resistant to igniting by compression rather than the spark, which allows manufacturers to increase the compression of their engines. A fuel mixture ignited by compression is called knock. Knock is bad. What occurs is the flame front of the compression induced explosion runs into the flame front of the spark induced explosion. Bang! This can cause internal damage to the engine. Sometimes it's barely audible outside the engine but inside...woo-boy!

If it says 91, use 91.

Wow! That is a mouth full!
Thanks!

Yeah, I know...sorry about that.

When I was young I always thought that high octane fuel burned hotter and easier. I was shocked to learn that the opposite was true when I became a technician. Consequently, it really stuck in my head.

One of the guys just made the comment that they were under the impression vehicles were trying to become more fuel efficient.