Which gasoline do you put in your RX8 (Regular, mid-grade or premium)?

 

I use premium right now, this is why I voted Premium but I am thinking to switch to regular.

 

I was told mazda recommends premium but there is no evidence that regular is harmful. The suggestion was to be consistant with whatever I use. With that I asked my sales guy "what did they use to fill my tank when I bought the car new?" He said it was not premium and most like middle grade so there you have it 89 for me.

 

I vote Premium with an * in front...

premium only if it's Shell V-power, if a Shell isnt around, i go with regular of any other brand.

 

I only put Chevron with Techron premium in my car. If I put another brand in the car idles hard and doesn't seem to have as much pep when I accelerate.

 

I put premium all the time...
Because the rotary engine runs so hot that you need to run higher octane to prevent detonation right? So that the timing doesn't have to be retarded so much by the computer thus giving you better performance... (wait.. was it retard or advance if the computer senses detonation? ^^) well something like that.

 

full tank premium cost be $44 today @ $3.43 a gallon

 

ok, if you read the manual it say you can use 87 but it may have the best performance, I use 93 or 89

 

I find the price difference is so small between 89 & 91/92 that I just use premium. Maybe i'd use midgrade if it was halfway between regular and premium in terms of cost. Here it is normally (not including this past week) 0.94, 1.02, 1.06 per liter for the different grades... to be honest i've only ever used premium so far, but with gas up at 1.35 per liter for regular... I'm thinking of switching!

 

no matter what the prices are, if its only $0.20 between regular and premium, it's always going to be $2.60 difference for 13 gallons. even if regular is $6.00 and premium is $6.20, for 13 gallons of gas, it will end up being $2.60 difference.

 

Then something is wrong with your car - or maybe this is all just in your head

 

Yeah, and this was not so with previous naturally aspirated rotaries that were known to prefer regular...

 

regular for me, better mileage better power. 15,000 miles in 4 months doesn't lie. I've driven them all and 87 wins consistently.

 

$65cdn for a tank of Premium.

 

Premium only. Tried mid-grade ONCE. Its amazing to me that people squawk about an extra 2.50 a TANK and think nothing of buying a 6.00 MochaChocalatteFrappucinesso at Starbucks. :D

 

It's not squawking about $2.50 - it's about having better throttle response and getting better fuel mileage with regular, all that without any obvious ill effect. But what do I know...

 

I just made the switch to regular last week, and have been slowly pushing the car harder and harder to see how it reacts to regular. So far, so good. I think I'm a regular convert. The car certainly doesn't show any ill effects from switching, even when running to redline. Certainly if it's at least drivable under regular city conditions, than regular's fine iwith me. Less carbon build up if anything.

 

exactly.

 

You obviously know SO much more...

 

To me it seems kinda dumb to spend $32,000+ USD on a sports car and then run regular gas and keep it under 3,500 RPM to save money on fuel costs. The car gives you a finite number of high performance miles before it goes to that great junkyard in the sky, why waste any of them?

I.M.H.O.

 

Mid grade (don't really see any difference between it and premium)

Just won't try regular. My RX-8 is better than that...

 

Shell 92 octane for my 8. She knocks bad under load when using 87 of any brand. The only time my 8 knocked on 92 was while using Chevron.

 

Some people seem to be under the impression that there is a difference in quality between regular and premium. This idea is simply a construction of effective naming and advertising by the gas stations. All three grades are very finely processed, and in fact a lot of times the regular has less additives in it than the premium. The label and octane rating mean nothing more than the speed at which the gas burns, which effects the likelyhood of it igniting prematurely under compression. Higher octane is a achieved many times by adding more junk to make it burn slower. This decreases the effectiveness of the fuel, but allows for higher compression before detonation, and higher compression means more power per stroke. Since the compression ratio in your engine is set by the physical characteristics of stroke length, shape of the chambers, and all that good stuff, if your car can run without predetonation on 87 octane fuel, you may as well save the 20 cents a gallon and buy the regular. You are not going to see a major difference, and may even get lower milage and performance out of premium.

If however, you experience knock or ping when running 87 octane fuel, you should run a higher grade fuel to prevent possible damage to the engine. Since your car's computer has a knock sensor in it, which adjusts performance to prevent knocking if a knock is detected, you MAY experience a performance drop using 87 octane fuel if your ECU detects a problem. If your car feels sluggish running a particular grade or brand of fuel, its as likely to be the additive mix as the octane level, unless you experience the same symptoms from more than one brand of fuel at the same octane level.

When I first got my baby, I put premium only in it. My highest and lowest milage records: 9 mpg and 22 mpg were set with premium, and my average was about 14 with 80% sitting at stoplights and 20% baiting cops on the freeways. Since switching to regular, my average is still at 14, and my milage still ranges all over the place. My car can handle 87 without any performance degradation, in fact a lot of times it seems peppier now, but that could be psychological.

What you do for your own car is your own business, but don't think that your car is "too good for" regular, because that is merely a perception that the oil companies want you to have, not a fact. Make your decisions based on what works best for both your car and your wallet, and enjoy your driving!

 

I have been using premium octane since the day i bought my car. The only brands fuel i get is from Conoco/76, Mobile, and Cheveron. I don't buy generic/cheap gas unless it's the only gas station for miles, and my gas light is on :p.

Sometimes though, when sitting at a red light my engine's RPMs drop from 900RPM to about 500RPM. I don't know if it's a problem with the fuel, the ECU, or something else. I should take it into the dealer for warranty, but they will probably say something stupid like "oh, we can't find what the problem is."

 

I always use High-test!