Hey - Just picked up my car yesterday, and I am about to fill up for the first time. I never have owned a car that recommended "premium" fuel. What are the upsides? Is 89 octane consided premium? or 91 and above?

Considering it will cost an additional 3-4 bucks per fillup, its not a huge deal.

Sorry if this was discussed in the "other" forum before....

Thanks - Chuck

 

Use 91+. See the owner's manual for the details.

 

91

 

which means 93 for me since we only have 87,89,93 here.

 

if i remember right, if the car has a octane sensor, it will change according to the fuel and your drive patern. BUT... the ECU in the American cars have changed to accept 91 Octane, not saying you cannot put higher octane racing fuel like 121 or up... Up here in northern california there are only two places to get it, San Ramon, or Sear Point Raceway... maybbe thunder hill in sacramento, but i've never been to that one. Eitherway I believe in regular driving and fuel economy, sticking with 91 is the best choice, even tho the 10 cents more a gallon at the station from a 87 octane, it really does make a difference.

Sincerely,
Peter

 

you will find 93 at stations near (below 1mile up) sea level areas... at higher altitudes you will find 91 stations.

anyway, you are best sticking with the recommended fuel which is 91/93... anything higher and you are wasting your money. Lower octanes will work at a performance cost and potential damage to your engine.

 

Where in San Ramon? I have a Jeep Grand Cherokee with a high-performance ECU that requires a minimum of 92 octane. The engine pings under load when it's 80°+ outside. I've even installed a low-temp thermostat. Octane boost helps quite a bit but I'd like to try some higher-octane gas. It ran great when 92 was still available and from what I understand, the ECU will utilize even higher octane.

 

Close. It has a knock sensor, when it picks up the effects of the lower octane gas then it will drop down to limp mode.

 

Usually, cars that require 91 octane can be operated safely using lower-octane gas. The knock sensors detect detonation and either retard or advance the timing accordingly. What this means to the driver is degraded performance and mileage (possibly rougher running too). Now this what usually happens. Not owning one yet, I can't say if this is true with the TSX (it was so with my S2000, is so with my Jetta, and is not so with my Jeep). However, if your owner's manual states that you should use 91 octane, just do it. The car will be more enjoyable to drive, you'll get better fuel economy, and your car will love you for it.