I have a 2005 rx8 with 39900 km and I only get 180 km per tank city driving.

Would a engine misfire cause the low gas mileage Im getting.

Let me know thanks

 

That's pretty harsh.

Do you feel any loss of power, difficulty starting or hesitation? If so then definitely check the plugs & coils.

Check your intake as well, it may be clogged.

What kind of fuel are you using? Any mods?

 

yes.. it would. Either a dead spark or coil could cause this.

This happened to me not to long ago.. and I was getting about the same consumption as you were.

The car was running smoothly for the most part until it started drowning itself with fuel in the cold and started spazing out.

 

I only use 91 octane fuel. I dont feel any loss of power but I do notice it takes about 3 seconds when i turn the key to start the car but it may be the cold causing this. as for the spark plugs and coils is it hard to replace myself? How many km per tank do you guys get just curious

Thanks let me know

 

Plugs are easy: https://www.rx8club.com/showthread.php?t=31872.html

I get about 420-450KM average. Most I ever got was 500 (CC@ 100 straight through the tank). Worse I ever got was about 320 (screwing around and driving it hard).

 

plugs are easy like what the link showed; but i dunno how hard could that be if replacing all plugs and coils and wires. but i went to ask dealer how much they would cost, the labour is around 60 bux for either coils or plugs. so 120 total basically. therefore, i am assuming it wouldnt be too hard

 

Im going to replace the spark plugs for now to see if my MPG increases any ideas which spark plugs to order

 

Try replacing your air filter, as that might be your issue

Then do plugs, coils, wires etc

 

Well considering you take off one side of the wires to do the plugs... job is 50% done.

Follow the wire about a foot and you're at the coils.

Really can't get any easier

 

Just ordered a K&N filter see how that goes

 

OEM plugs are the best.

Unless your filter is extremely cruddy that won't help much for mpg

 

just an update on the situation well I ordered sparkplugs and when i went to replace my plugs. Guess what I noticed one of the wires was off the spark plug this must have been the reason for such bad mileage and loss of power I was only running on three plugs.

Any ways I replaced the plugs and reconnected the wires and now the car is flying what a difference in power. I dont know about the mileage yet because havent filled the tank yet since replacing the plugs today. Hopefully mileage will improve dramatically.

 

That's so high! I only get 300-320KMs on average and that's when I'm already doing 40% highway and not driving hard. Would the type of fuel cause the difference in mpg?

I use Sunoco's 94 Octane right now, I find that the engine runs smoother with 94 than 91, especially at low RPMs going at low speeds.

 

450!!!! wow i wish i got that, and i drive about 75% highway.... but its rush hour driving...

 

I've only done a few tanks, but I've gotten around 350kms from ~52-54L of almost exclusively city driving which is 14.9-15.4L/100kms.

 

I can easily break through 400km when I do 50/50 driving.
Last time I did 410km on 49litres... and after the light I can do around 40-50km's.

23MPG 50/50 city/highway driving FTW!

 

Wheel alignment makes a big difference on fuel economy.

I had 17.5 MPG for five months (The months I was recording)

Then I chambered my rear wheels.

Now I get 15.3 MPG on average.

Wheel alignment is big difference. (I also hear tire pressure adds to this equation)

 

I run Esso 91 + 400:1 premix.

Mileage has been a bit worse this year, probably because I am driving mostly city and pretty hard (hitting 320-360 lately).

 

One of my plug wires came off as well somehow over the winter. I could hear a weird noise. Sounded like it was something clicking under the car, I decided i'd check the engine bay and there I could see the plug-wire arcing with the plug. Easy fix

My gas mileage is erratic. I was getting mid 300's when I bought it, low 200's last fall and high 200's this spring...

This here particular tank i'm unsure if i'll even see 200kms lol... A lot of it has to do with what RPM you tend to run your car at. This last tank i've been running it a little higher due to some raspy-ness at certain RPM's after installing a mid-pipe. I'll be installing a resonator soon to help with that issue.

 

around 350km for me in city driving. I hate city driving. Now my v6 mazda6 wagon is amazing. It will hit 550km in a full tank on the same type of driving! It's also auto.

 

350 to 380 KM no matter how, where, or at what speed. Tried slowing down>>same Drive Hard >>same, so I drive how I feel. Enjoy the ride and to hell with mpg. IMO
Used Octane 94 for ever, now I use 91 >>>> Same, but less carbon build-up and save a couple of cents!

 

Ditto! Who buys an RX8 for the mpg???

 

unpossible!!! what rpm you shift at???

 

probably like 2,000 for everything >.> and stay under 3k all the time =) LOL maybe that would work...or he just uses neutral A LOT, but even that might not work

driving like a granny might though. Hybrid Driving Style FTW

 

Almost no people. But i have heard of many people who had to return/sell their RX-8 cause they couldn't afford the gas for their car.

A tragedy, but still, it occurs.