Gas mileage?

[bhw33191]

Today when i filled my tank, i did the math and was shocked to find i got 7.7mpg!!!?? I'm assuming (and hoping) its because its winter (more time spent idling and also gunning it trying to get unstuck).

So i was wondering what you guys (specifically carburated 305 owners) are getting? Input from anyone else and what they get is welcome too.

[beat88ls]

Originally Posted by bhw33191

Today when i filled my tank, i did the math and was shocked to find i got 7.7mpg!!!?? I'm assuming (and hoping) its because its winter (more time spent idling and also gunning it trying to get unstuck).

So i was wondering what you guys (specifically carburated 305 owners) are getting? Input from anyone else and what they get is welcome too.

damn dude, i was getting 13/14 mpg when i was driving mine every day, carbs suck... no pun intended.

[mike561]

I'll have to try n remember next time i fill up, probably no more than 17 for me if im even lucky to get up to that much. too bad we dont have those digital gauges in our cars that calculate that stuff for you

[RageCage]

BHW,

My box is an 85 classic with the 305 carb. I get 19 to 20 mpg in winter and 21 to 22 in summer. My usual drive is 80 miles a day commute to work, and it's 80 percent hiway.

RC

[bhw33191]

Originally Posted by RageCage

BHW,

My box is an 85 classic with the 305 carb. I get 19 to 20 mpg in winter and 21 to 22 in summer. My usual drive is 80 miles a day commute to work, and it's 80 percent hiway.

RC

Ok thats good to know. I guess this means somethings wrong then. Which makes sense cuz she still ain't running right. But its sort of discrete. It idles kind of jumpy but i don't know if that has anything to do with it. I've replaced almost everything i could think of so i don't really know what to do.

[RageCage]

Originally Posted by bhw33191

....its because its winter (more time spent idling and also gunning it trying to get unstuck).....

bhw,

I have the quadrajet carbed 305 caprice ( 1985).

The colder it is, the more the engine races, for me, when I start it up. I can try to kick it down but it just keeps wailing, like at 2500 rpm. I just drop it into gear and drive easy on the throttle until it warms up, and eventually, when the engine warms up, the idle drops. I think the heating element in the electric choke is shot.

Even so, I get 19 to 20 mpg in winter.

I once had a very dirty air filter, and replacing it gave me better mpg.

btw, I have new plugs, and new air filter, cap and rotor are new, and wires are only 3 years old.

[bhw33191]

Originally Posted by RageCage

bhw,

I have the quadrajet carbed 305 caprice ( 1985).

The colder it is, the more the engine races, for me, when I start it up. I can try to kick it down but it just keeps wailing, like at 2500 rpm. I just drop it into gear and drive easy on the throttle until it warms up, and eventually, when the engine warms up, the idle drops. I think the heating element in the electric choke is shot.

Even so, I get 19 to 20 mpg in winter.

I once had a very dirty air filter, and replacing it gave me better mpg.

btw, I have new plugs, and new air filter, cap and rotor are new, and wires are only 3 years old.

Wow yours races too when its cold? I thought something was wrong with mine for the longest time but i guess not. I remember after an ice storm one day i had to move my car and the wheels were spinning even at idle cuz it was trying so hard to get warmed up. And the other day when it was about 12 degrees i let the car warm up for 5 minutes but even still i couldnt even touch the gas without it bogging down. First time that happened too. Typical of an older car but hey, gotta love em.

[96capricemgr]

Forgot how good we have it with the sequential port injection. I get upper teens mixed driving with the sedan 3400stall converter, 3.73-4.10 gears(had both) something over 470hp naturally aspirated. Then again what I have spent on modifying this thing could pay for a tanker of gas. That one gets premium due to hig compression.


The wagon gets upper teens to low twenties mixed and mid twenties highway.

[j cAT]

Originally Posted by bhw33191

Today when i filled my tank, i did the math and was shocked to find i got 7.7mpg!!!?? I'm assuming (and hoping) its because its winter (more time spent idling and also gunning it trying to get unstuck).

So i was wondering what you guys (specifically carburated 305 owners) are getting? Input from anyone else and what they get is welcome too.

If you live in MA you know it has been zero f temps...this will kill your MPG....especially on the carb engines....10mpg driving in snow and with these temps its very expected....this is not the time to measure your MPG too depressing...

if you have the hot air exhaust manifold tube hooked up to the air cleaner, and insulate the tube this will improve this as the carb air will be warmer and aid in vaporizing the gas,,the very cold gas...

[bhw33191]

Originally Posted by j cAT

If you live in MA you know it has been zero f temps...this will kill your MPG....especially on the carb engines....10mpg driving in snow and with these temps its very expected....this is not the time to measure your MPG too depressing...

if you have the hot air exhaust manifold tube hooked up to the air cleaner, and insulate the tube this will improve this as the carb air will be warmer and aid in vaporizing the gas,,the very cold gas...

Advice well taken. I'm getting really annoyed with all this cold weather and snow we've been having and the low mpg doesnt help.

[bhw33191]

Update: Today i filled my tank, did the math again and got 8.6 mpg yay! Thats almost ONE mpg more than before. I think it got better cuz i took the advice of going easy on the throttle if ur stuck/slipping in the snow.

[Blue Bowtie]

Check your choke. Set the MC solenoid lean and rich stops, and set the curb idle. Set the base timing. Then, and only after all that is done, set the TPS voltage.

You should be getting better mileage than that unless you do all stop-and-go driving.

[bhw33191]

Originally Posted by Blue Bowtie

Check your choke. Set the MC solenoid lean and rich stops, and set the curb idle. Set the base timing. Then, and only after all that is done, set the TPS voltage.

You should be getting better mileage than that unless you do all stop-and-go driving.

The way i get to school its all stop and go most days so i guess thats it.

[RageCage]

BHW,

My 85 didn't always rev high in cold weather. It used to be like a normal car : rev high for about a mnute max, then come right down to normal idle, even in cold, cold weather. I really think it is the electric choke heating element which has burned out or corroded, or been otherwise borked. A coworker, who is a mechanic, told me he thinks it's the choke heating element. The fix is to drill out the cap on the choke , buy a new element (if you can find one anywhere. Haven't looked for one) and replace it.

I just live with the problem. I hear you about the spinning wheels. The rear wheels keep turning when you come to the stop sign, on the ice and snow !!!!

LOL.

[bhw33191]

Originally Posted by RageCage

BHW,

My 85 didn't always rev high in cold weather. It used to be like a normal car : rev high for about a mnute max, then come right down to normal idle, even in cold, cold weather. I really think it is the electric choke heating element which has burned out or corroded, or been otherwise borked. A coworker, who is a mechanic, told me he thinks it's the choke heating element. The fix is to drill out the cap on the choke , buy a new element (if you can find one anywhere. Haven't looked for one) and replace it.

I just live with the problem. I hear you about the spinning wheels. The rear wheels keep turning when you come to the stop sign, on the ice and snow !!!!

LOL.

Yeah its really wierd. It revs high like a normal car for a while and then it will start to slowly go down...but right when i think its done revving away it'll go right back up to 2000+ and keep going through the cycle up and down like it doesn't know what its doing..yeah it must be that heating element, sounds like a pain to replace though