WTF 160 miles on a full tank
 

So I bought this 04 RX-8 2 months ago, thought it'd be fine with the car running on a full tank everytime for 160 miles, but as i read on, other people seems like getting much more than 13 mpg, so can anyone tell me what could be wrong with my car? :Eyecrazy:
Sparks plugs? tires? uh... idk... What could be wrong?? :banghead:

And please for those people who are just trying to tell me what gas milage they are getting, you are not helping...

O, and btw, sometimes it takes about 2-3 seconds to start
just a thought it might help u guys figuring it out...
Thanks

I get 25 city and 33 highway.

Coils. Spark plugs. Spark Plug Wires.

24mpg city/highway mixed.

Period.

.

I just Seafoam my car.
And I got 210 miles before the empty tank light is on with 50/50 city & highway drive.

I didn't have 200 miles per tank for a while already.

meh i get 150 to the last quarter, with new engine, new coils, new plugs, and a rebuilt transmission thats making a new weird noise

i also can get to 200, driving style makes a massive diffrence, sad this new engine seems to get worse hwy mpg then my last one.

clogged cat?

d00d, guiz, I once went 600 miles with only a quarter tank. TOP THAT!

Coasting ftw?

clean the maf sensor

I just drove two nights ago on a full tank of gas and got 345 miles to the tank. Personally, I don't think that is all that great for windows up, straight highway driving at 75 mph and the air conditioning off half my drive. I think that is what, 23.8 miles to the gallon?

bah, after i installed HKS racing suction and legamax exhaust, 1 full tank is now 250 miles, don't know why, and don't care! lol

I go along with Shazy's recommendation to check the ignition stuff. 2-3 seconds of cranking is excessive. With the original ECU, these cars start almost instantly. After the 4206f flash, they'll start after a couple of revolutions.

What kind of driving do you do? Highway? City? Meek? Spirited? 13 sucks, but it's not outside of the range that people talk about here.

Ken

i usually fill up whenever i reach 1/4 tank left and i do 100% city driving with a LOT of spirited driving every day i drive and get about 160 miles to 3/4 of a tank.

the 2nd day i had the car i drove to dallas, tx and back and averaged 85 miles to each 1/4 tank i used

Honestly, what I've been observing lately.. especially since I've been tracking my gas mileage...

Tune up (normal plugs, coils, etc) will help a pretty good amount, depending on how bad it was in the first place
Assuming your engine is running fine, It's really just driving style

I can also easily hit 160 miles on a tank, if I constantly drive at school where it's pretty much stop and go. You're not going to get much better without hitting the highway.

I honestly think.. after nearly 70k miles, that about 22 mpg+ is only reserved for the highway.

BUT surprisingly, I found that (at least in MY 8) when i speed, I get BETTER gas mileage vs. 65. Honestly, I can hit 75+ miles per quarter tank when cruising at a higher speed while I will only get 55-60 going a lower speed.

Not endorsing speeding, but it's something to think about.

Ignition system...Coils ,Leads, Plugs.

Tires..make sure you have enough air in them, can make a 5-10% difference.

MAF Sensor Clean.
Blocked or dirty air filter element?

Have you tried Pre-mixing, IMO you get better compressions because of better sealing between your metal seals, etc. (apex, side and corner seals).

Fuel grade or quality...use premium, I get better mileage when I do.

Engine oil, yep, this can also have a slight effect on MPG, how long ago was the oil and filter changed?

Pre-mixing ftw :D:

i got an ignition upgrade, changed the plugs about 10-12k miles ago (same time as the ignition upgrade), highflow cat and i still can only get 160-180miles on a tank of gas, car seems to run fine i dont notice anything strange, i def wish i could get an extra 30miles to a tank or so

What's your tire width? That makes a big difference too.

I get 16-17 mpg with a Cobb tuned motor, AEM CAI, Greddy Evo TT exhaust, and 245/40/18 F 275/35/18 R. Plugs and coils have about 8k miles on them.

my first two tanks after buying the car were 170 miles per tank. Now, using 87 octane I see 240-250. Using 92/93 it's about 215-220.