extended warranty & gas grade
 

waiting for delivery of my rx8. Would love some feedback on two items. In canada Mazda offer 7 year ext warranty for $1,500 Canadian ($1,200 US), without really knowing the reliability of vehicle or potential major problems not sure if I should grab it. Also we have 3 grades of gas- regular, mid grade and high test.
Dealership suggest high test. What do you use? I understand there could be a warranty issue if you don't use high test.

I did get the extended warranty as this is a new make of car and there may be some powertrain issues with it in the future I thought best to CMA (warranty goes up to 100,000 miles now).

I use 93 octane (high test) as I don't really see saving a few cents per gallon as being a big deal. People on the forums have been running 87 and 89 with no problems though. I'm not sure about gas grades voiding the warranty though (it would be pretty hard for them to prove what gas you are using on a regular basis, although I guess they could test what was in your tank).

after the m flash if i use 87 it really hurts my gas mileage so now i only use 91

$1,500 for 7 years? That's a good deal! I paid, I think $2500 for
the warranty (and that was only 2 weeks ago).

Because of the rotary engine, I thought it was a good safety net to go for the extended.

Oh .. and the car prefers 91 octane. I don't think it's wise to deviate from the manual.

The manual that I have on pdf recommends Premium Unleaded Fuel 91 [(R+M)/2 method] or above (96 RON or above).

It goes on to say:
Do a search, you will find A LOT of discussion on octane.

I've split the difference and use the mid grade fuel. I have done some long road trips and haven't noticed any appreciable difference between mid and high grade fuel. No better milage and since I'm not running a road race, no real difference in performance.

I always use 89 octane - i'm getting better gas milage then most and I really don't care if my 0-60 time is .3 sec slower on my way to work while stuck in traffic jams :o