I've read that a third gen f-body gas tanks holds 15 gallons. Can anyone confirm? my gauge is messed up so I can't use it to know for sure. i've got an 86 iroc. thanks.

 

15.5 gallons. Some of the early years may have been different. Do you still have the owners manual. If so that will tell you.

 

Thanks man. no, I don't have the owners manual.

 

My '82 holds a tad over 14 gal.

 

theyre all about 15g

 

15 gallons sounds right

 

when my gague says E, and i drive 5 miles to the gas station, i can put in about 14 gallons, 14.2 is the absolute most i have ever put in... so im guessing 15 along with the rest of the guys

 

15.5 gallons no mater how much you put in the tank. Again 15.5 US gallons.

 

they varry depending on engine size and options, from 12 gal to 17 gal, most cars got a 15.5 or a 16 gal tank, mine came with a 16 gal

 

thanks guys. based on your responses, when my gauge says empty it really means half full (it takes 7-8 gallons to fill at that point), which is what I suspected. exactly what I wanted to confirm.

 

You have RPO codes to prove this?

 

It was in my old chilton manual, which is in storage (I'm currently in korea, with the AF) also classic industries sells factory reproduction gas tanks in varrious sizes depending on the year, engine, and options, the catalog usted to specify which size was which, but they went to just car info as of about a year ago.

 

According to my '84 Trans Am owner's manual it has a 15.9 gallon gas tank. With the gas gauge almost down to Empty I can usualy put in almost 14 gallons so a 2-2.5 gallon "reserve" sounds about right.

 

I emptied mine out and it took ~ 16 gal to refil it (the chiltons manuel also said mine was 16), but mine says E and it takes about 12.5-13 to re-fil it, our gauges were never really that accurate, when I get my digital dashbord I'll have to see how accurate the sending unit is

 

Why would GM use more than one size tank for different engines/options? I have a hard time buying this. I could see different sending units/baffling making some difference in volume, or possibly the tank being distorted slightly during manufacturing, but I doubt the tanks were deliberately made in different sizes. That would mean tooling for different tanks, added complexity in assembly, different mounting hardware, etc. We're talking about a company that recycled the 3rd gen's back-half engineering into the 4th gen to save money.

 

I don't have my chiltons manuel or my OLD classic industries catalog, but I have the new one and there were are 16 diffrent applacations for various diffrent tanks.....I don't know mabe someone at GM got a bug up there a$$ when it came to making tanks.

 

IIRC the manual says something like 15 or 15.5 gallons, I know that when i topped my tank up I got something like 50 liters in it, which is maybe 12 gallons

 

i wanna see the RPO codes for these 50 different sized tanks.

 

I could see different part numbers for some year changes, EFI/Carb apps. and a better baffled tank for performance options, but I can't see the size change for different engines. I'm not saying it's impossible, just that I am skeptical about cheap ole GM spending an extra buck. Perhaps they increased in capacity over the years as production moved along. Either way, inquiring minds want to know.

 

the only difference in tank size i could even think of would be if the fuel pump was in-tank or external, but even then i dont think it would change the capacity by whole gallons. still interesting... my chiltons and classic industries doesnt say anything, but both of mine are newer

 

This thread from the FAQ board has a scan of the chart from a Chilton manual.

https://www.thirdgen.org/techbb2/sho...hreadid=242850

 

I believe the chart in the link above is correct. My 1985 Camaro Owner's Manual clearly states that the fuel injected cars received 15.5 gallon tanks, and the carbed cars received 16.2 gallon tanks.

 

I thought it had more options than that...oh well, that's what I get for going from memory