Looking4RX8

Hey Guys:

The Rx-8 brochure suggests to use Premium fuel. Does everybody follow this? Are there any major risks involved with using regular gas? Cheers!

BlueFrenzy

Search brother search. Tons of threads on this. Keywords like octane, gas, regular, etc

Anyways, the manual says that octane 87 and up is acceptable ... just that there may be a difference in performance. In my experience, lower octanes give better mileage but when really cranking the 8, the acceleration is NOT as hard (compared to high octane). You should be concerned only when you start hearing pinging or knocking noises from your engine as that is the fuel not being ignited at the proper time (hence knocking the rotors) ... at that point, switch to higher grade and have the car checked out just in case.

With rising gas prices lower octane is definitely more attractive but think of it this way.... if you cut down on pop/cola, doughnuts or your daily starbucks .. you'll have more than enough for premium. Besides, you'll lose weight, be healthier and it'll make your 8 go faster because it'll have to lug less of your fat ***!

scoop

There is tons of debate elsewhere on this. Most performance cars of any sort recommend it to avoid preignition which is bad for an engine and particulary bad for rotories. They have higher compression ratios that increases this risk. Knock sensor feedback to the ECU will cause your timing to be retarded and you will lose performance if any preignition is detected. I would not make a habit of relying on that though and would only use regular if nothing else was available and my tank was empty. It's simply not worth it to go out and buy an expensive sports car and then degrade its performance and put it at risk for the sake of a few cents a litre on gas.

At a 10 cent a litre premium if you burned 50 litres a week you would be paying $130 a year extra for the premium gas. That's on a $2800 gas bill on $40K car and when you tack on other costs like insurance, maintenance and cusumables like tires the extra gas money doesn't seem like much . . .

him

Actually... Just checked with my calculator... at 50L per week, that's $5 extra per week... which, since one year has 52 weeks, is actually $260 extra per year. :p

But yeah, that's still worth it, i think...

BlueFrenzy

Like I said ... less coffee/doughnuts = more zoom!

Let's say $3/day on coffee/doughnuts (yes ... cheapo coffee) x 300 work days (assuming lots of holidays!) = $900 going into your blubber

Rontec

You work on Saturdays and Sundays?

RotrDoc

I don't spend on coffee/doughnuts (brew my own coffee and don't eat doughnuts) and my ***, at 180, can't be lightened very much. But I can easily afford the extra $300 a year for premium (at 24,000 miles/yr, he's now pushing 45,000).

I got a new engine at 36,000 under Mazdas "high mileage engine swap" program, and the new engine hasn't seen a drop of gas under 91 octane. And won't.

Rotator

94,91,89 - Don't notice much of a difference.
I have logged since new - 14.17L/100km.
Haven't gone below 89 though
Worst? 29.86L/100km on 94
Best?
10.85 on 94
11.13 on 91
10.98 on 89

Basically all of the same - Rule of Thumb - cruising on the HWY, there is no need for 91,94. 87 will most likely work well for you
Track? 94 - why take the chance.
Spririted driving - 91, or 94 - again - why take the chance?
This is an NA engine - I don't have specific numbers on the affects of acceleration, but lets face it - the 8 is not a fast car. Quick yes, fast?

I should tally up the results of averages for 89,91,94. I should have at least 8000km of each type.

I read somewhere that the RON was low anyway and Canuk gas was better than US gas.
I only use Esso, or Sunoco. Ever since that Shell fiasco...

apaul

[QUOTE= Ever since that Shell fiasco...[/QUOTE]

Could you elaborate on that a little more,please? I have been using their much-hyped 'new' Premium V for a month and so far, the mileage and performance claims, though not dramatic, and without the 'R' flash-getting it this Monday-are evident .. Thanks.

scoop

I believe there was a class action case against Shell for damaging fuel senders and stuff on a lot of cars because the fuel mixture was very corrosive. I think that is probably history now, goes back a year or two.

apaul

Thanks, scoop. My socially-conscious son calls Walmart and Shell, among others, 'evildoers'

Hellbreed

I find Esso gives me the worst gas mileage by far, this is not a once up occurance this is fairly constant and instintaneous on that fillup. Sunoco 94 isn't too bad but and use it from time to time, I've been sticking with Petro Canada and get the best mileage on it with 91 Premium. These are the average numbers I get from the three based on my driving style:

Esso: 320-340 Kms per tank
Sunoco: 340-360 Kms per tank
Petro Canada: 360-380 per tank

The interesting thing is that I just recently told my wife this who drives a Mazda Tribute and usually fills with Petro Canada also. She out in Esso on her last fillup and she said she got 30 kms less on her tank then with Petro Canada. If you haven't used Petro give it a try, i'm curious to see if your mileage increases also.

apaul

I strongly agree with you re: Esso (ughh) and Petrocan.. (a winner). Pioneer as you likely know is rebranded Sunoco. ON the recomendation of my mechanic I have often used Premium 91 (Sunoco 94) and have been pleasantly surprised by the perfomance and mileage. Often it is a cent or so cheaper than 94 and those bonus bucks can add up to make a worthwhile saving.

Lawyer's Spirit

Damn I didn't know that. Pioneer here I come. For reference I use premuim in boosted rotaries but I always ran regular in my N/As.

apaul

HI LS: by coincidence I just had the 'R' flash and the starter motor upgrade at Whitby Mazda then headed across #2 to the Pioneer. Damned if the young guy who served the 91 also works at the Sunoco on Thickson and 401. I asked him if my info was correct and he confirmed that Pioneer 91 is Sunoco 94. Then he did a price comparo on line.. 91 was $1.09 and 94 $1.14 at noon today. So, sometimes urban legends to prove to be true!

Cheers
Alan

Rotator

Esso vs. Petro Canada?
91 Pioneer = 94 Sunoco?

Hellbreed - Average numbers? What are you talking about? Statistics - Give me the details - I find it hard to believe that you are getting 10% better economy between Esso and Petro.
To give you an example - here are some of my numbers L/100Km - usually all for a full tank.
14.19 17.67 16.08 10.85 29.86 13.83 14.40 15.30 12.41 10.78

Look at the numbers - they are all over the place. What makes you think that Petro is better? I think you would need at least 10 fill-ups of each to make any kind of statistically relevent claim.

As for Pioneer - I like the 3X bonus bucks - By far the best deal in terms of incentive.
Too bad there aren't many around. I try to visit one when I can.

91 is 94? New math - Cool!

dabuda

interesting topic... good to know for a noobie who wants to buy an Rx-8

yes those bonus bucks at Pioneer are great incentives, but i find it now that Pioneer Gas isn't getting any cheaper.

crocketboon

Has anyone tried alternating filling up one week with premium and the next with regular? It's getting a bit old paying for premium always.............

Smokin_LaLa

stick to premium.......with the way this car is i only go with premium

DarkBrew

I always run premium
I was using Petrocan but switched to Shell Vpower as an experiment. I've not seen a significant change in mileage but with temperature changes, traffic and driving style all contributing it's tough to really tell.