alnielsen

iTrader: (4)

Probably not. The PCM will automatically make the necessary changes if warranted. If it was a catback, definitely not needed.

tommy_ed

i'll try not to take it personally, we have the same problem at android forums with people asking about task killers, so I understand. See ya guys around, next time I'll ask how many cylinders the rx-8 has. LOL

tommy_ed

just unhook the battery for about 5 seconds, then re-attach!

alnielsen

iTrader: (4)

Must have 4, there are 4 spark plugs aren't there?

It probably takes more than 5 seconds to totally reset the PCM. I'd wait 60 sec.

paulmasoner

iTrader: (1)

for some reason I have it in my head that there is some parameters that dont resent unless you're disconnected for like 20+ minutes??

damnit, now i'm gonna have to go look that up cause its gonna annoy me not being sure WTF I'm thinking about

alnielsen

iTrader: (4)

Your probably right. I never disconnect the battery unless it is to work on the car. I never worry about resetting the PCM.

9kBeep

when i reset the battery i disconnect the negative wire, pump the brakes for about a minute just to make sure i get all the access electrical current out of the system. then i will let it sit for about 20 minutes, then i will reconnect it. start it and let it idle for about 10 minutes.

everybody has there own method but i like this the most for me. when i did this to my last car, every 5-6 months or so it would actually increase the mpg a tad bit and the car felt like it ran much smoother. it can never hurt to seset the computer it acts as sort of a "refresh". just like your computer at home your PCM can get backed up with a bunch of useless info that can confuse it a little and change the parameters of that which it would normally run off of. i dont know if this is entirely true but i have convinced myself of this.

jasonrxeight

Saving is a relative term really. you may save a few bucks when filler her up, but then you get less millage outta same tank of gas. also if the engine does knock, you risking damaging the car.

DocBeech

iTrader: (1)

Stomp the brake pedal theory for anyone?

If you drive the car proper your fuel mileage is going to suck. I have owned a lot of sports cars but if I ever wanted effeciency I would have bought a ford fusion or something like it. Its just how it works. I know our economy isn't great, but we are actually averaging around the same that the 350z is getting if you check fuelly.com so meh give or take how you wanna look at it.

PSTNLSS

iTrader: (3)

So the diesel I've been putting in the car for the past 3.5 years was a bad idea? No wonder she never ran right.

xexok

Sad but true, I was thinking that while I was reading this thread. The highest I cant find in vegas is 91, with I guess a few places that sell 100 octane but I have never seen them only heard of them.

DocBeech

iTrader: (1)

Here you can get 93, 100, 110, 110LL, 120, and 140 octane.

REDRX3RX8

From someone who delivered fuel for 38 years, diesel is the most likely contaminant for gasoline during delivery, and raises the heat load on the engine.

Gasoline can be run in a diesel engine at up to 50% in the winter, but the explosiveness of the fumes is dangerous, because the left over fumes in a gas tank are too rich to burn, and in a diesel tank are too lean to burn.

I even let 2 or 3 gallons of kerosene (diesel #1) get in my 20 gal F150 tank while I was converting a tank to another fuel, the oil become blacker, and the rings gave blowby about 10,000 miles later.

Diesel has more btu's, and is designed to fire differently as in more knock than gas.

If anyone wants to lubricate fuel as a premix, get something that's been tested, and used by 2 stroke guys for piston and port cleanliness, and wear.

There's a very good test of different 2 strokes in Rotax ultralight airplane 2 strokes.

It seemed that Pennzoil air cooled 2 cycle was good.

REDRX3RX8

Las Vegas is approx 2100ft so 91 is plenty high for there.

The rule of thumb is one less octane necessary for every 1000 ft altitude, so 93 near sea level -2= 91Oct.

When you get into those special high octanes for aircraft, the ratings change to research oct which is slightly higher to start with.

Just use the highest octane (90 to 93) that's generally found near you and you'll be fine.

If you're smart enough to boost, you'll know the finer details.

dezau

iTrader: (3)

lol if you think this was flaming, you shud read this
https://www.rx8club.com/lounge-4/last-lowered-my-2-cars-already-209061/

Jacob6875

I don't understand why you would even buy an RX-8 if you are concerned at all about saving money at the fuel pump.

The people who made the car designed the engine to run on Premium fuel so that is what I would use. Just not worth it for a small savings to go against what the people who made the car recommend.

ken-x8

That's my belief as well.

The 8's owner's manual, as well as manuals for lots of other cars that specify premium, says that you can use down to 87 with a reduction in performance. There is a tradition that cars in the US should be able to run on 87. That goes back to the widespread introduction of lead-free gas back in the 70s, and is made possible by knock sensors. There may even have been a regulation about 87 back then...anyone in my age group remember anything about that?

Whether it's just tradition or actual rule, Mazda does make the 8 such that it won't be hurt running on 87, just lose some zip. There are a number of posts here by people who use 87 and claim they get better performance and/or mileage than with premium. Not that I'd willingly use 87 in mine, but such posts do add to the discussion and entertainment value of this forum.

Ken

dezau

iTrader: (3)

with the price of the 04 8 plummeting to almost 7-8k range, i expect there'd be more and more threads like this...

xexok

It seems like a good idea in theory, cheaper gas means you save in the long run. Then you look at the actual difference in price between going premium and mid and its probably 10 to 15 cents a gallon. So a full fill up and your saving a whopping $1 to maybe $2 so like $10 a month at the most?

As others said I always run what the company suggests, and it says right when you open the gas door "PREMIUM FUEL ONLY" so I went with that as a pretty good indication of what to use. My last car suggested mid grade, and thats what went in it.

Tweek

Im pretty sure it says Premium recommended actually, ive used regular for over a year with no problems or issues, i get better gas mileage with it and save a few bucks here and there.

tonik

OP, I'm using the recommended 91 Octane rating because I trust those Mazda Engrs who spent a lot of time doing the research..developments..experiments..
with proper equipments and tools and come up with those numbers.. considering how many engines they blew-up...

Plus, I've tried to use 89 octane then switch back to 91 because i fell i loss power and I've heard some weird engine noise. And I don't want to be a Mazda Engr..lol..

For savings$$$, I don't see that much difference unless you go 87 octane.

So, go.. give it a try to satisfy yourself and report back to us..

DocBeech

iTrader: (1)

The RX8 has a knock sensor. If the vehicle detects knock, it will retard the timing and prevent engine damage.

xexok

My sticker says "Premium Fuel Only Super Unique" its possible its been changed over the years they made the car though, but that's what it says for an 09.

paulmasoner

iTrader: (1)

wow, a lot of people have now idea what octane is, means, and how gas works. and this has happened here before

dezau

iTrader: (3)

it's good that the OP isn't a pilot lol, i'd be interested to see someone put 87 in a Cessna