Do old spark plugs effect fuel mileage, my 89 GTU only goes 150 miles on a half tank. Is this normal?

 

Shoot, 150 miles on a half tank is doing good! You really need to compute your fuel economy - fill up the tank and zero out your tripmeter, drive it unti the gas light comes on, fill up, and divide your mileage by the number of gallons you put in.

Stock, a non-turbo gets around 17-18 city and 26 highway. My '86 base gets right at 19 city and I've seen as high as 29 highway. My '88 Turbo (with heavy mods) can get 16 in the city, but usually gets around 12 since I can't keep my foot out of it . I've seen around 21-23 on the highway in the car.

Yes, old spark plugs can affect fuel economy, but it doesn't sound like you have an economy problem. The RX-7 isn't the most fuel-efficient car on earth, BTW, but it does pretty well.

Dale

 

What size is our tank, 15 gallons(I forgot)? Think its somewhere close, so that means hes barely getting 10mpg. Very shitty IMO. Do a full tuneup and then drive around, shifting at 3500rpms or before(VERY difficult). Then you'll see the potential of your gas mileage.

 

Eh? Where are you getting the math - 150 miles on a half tank means 300 on a full tank. 15 gallons in a tank = 20 MPG, which is great.

The tank size is around 15 - it's 15 and some change, really. I think it's rated at 16, but 15 is the most I've ever put in.

Dale

 

fuckign hell

in my mates r100 wed be luck to get 150km to the 55l tank

13b pp 51m ida weber 330hp doesnthat explain it

 

S4= 16 Gallon gas tanks

S5= 18 Gallon gas tanks

 

Right on my man.
My best distance on a full tank (usually fill up 13-14 gallons, 2-3 gallons left) is 250.
18mpg avg.

 

I get 17-18 city and less when I wear steeltoes but I get a consistent 20 on hwy, though I have seen 22 I drive an S5 n/a with fresh tune.

 

Duh.....What happened to this forum.....hayes manual says it all, you people should really get one 16.6 gal for all 2nd gen Rx7s

 

Oh, I apparently didn't read too carefully. My fault, thought he said 150 miles to a full tank. I get 20mpg in my TII if I shift at 3500 rpms or before. That only happens when I really really really try though.

 

17 mpg if I drive like a granny!!!

 

Please don't tell me. Another reason why the Haynes manual sucks!?!?

That is wrong, so very wrong. S4 is 16.6. That is what the Haynes morons had to work on. The S5 has a bigger tank. I guess I'll add this to my "Why the Haynes manual sucks" section.

http://www.zaxjax.com/HaynesManualSucks.htm

Go to beyond the redline for some real numbers.

 

Yep, Another reason that the S5 were heavier.

 

crap...my 88 AE only gets about 14mpg mixed city/hwy!!
and that's AFTER i changed the plugs and plug wires!!

 

try changing all your filters and O2 sensor