Early Chevy 305 Gas Mileage??

[VileZambonie]

Stewart, I understand you would like me to provide you with links and articles to prove this notion however I do not have time to do this. You can easily find this info yourself if you do some research. If you have your doubts look around online but do it in reputable places not like that link you posted of that messageboard, with a ghetto rigged air cleaner. Don't believe everything you read on the internet as there is a lot of false information repeated out there. Pick up a book on Automotive Technology like the Erjavec 5th edition

[Stewart G Griffin]

Yes, i think this topic is not cut and dry and will require more research.  i can't get a clear answer;  Some say yes, some say no.

This will take more time to uncover as i am busy too.



And i know about the trustablility regarding wikipedia entries, but for now:

http://en.wikipedia.org/wiki/Heated_air_inlet

[VileZambonie]

Again, what it is saying to you is in order to atomize the fuel when the engine is cold it is heating the air. When the engine is up to temp the thermostatic air cleaner no longer draws in warm air. The factory set up on our trucks draws the air in at the grill when the mode changes.

[jaredts]

Stewart, I found the links interesting.  Thanks.  Not sure I buy it, but what do I know.  As for the thermostatic air cleaner, like said before it doesn't draw in warm air for very long anyway so I'm not sure its relevant to better mpg's.  Back to 305 fuel economy:  You'll be lucky to get 15hwy/11 city.

[Lt.Del]

all the trucks i have owned have had hoses that lead from grille for fresh "cold" air to the air cleaner, that are about 4 inches in diameter.  The Feds have been putting pressure on manufacturers since the oil crisis of '73 to increase mpg's.  Why would they put in a fat hose to feed the carb clean cold air if it would decrease mpg?

[cherrycj7]

Jaredts, 11 city, 15 highway, why do you say that. I mean, is that from expierience? With around 10mpg's now with my 232 I-6 wouldnt the better power to weight ratio with the 305 give better results? like 13 city? torque would be going from around 190 to 240ish foot pounds. Do others agree with this thought? Would the early 80's 305's have any better gas mileage do you think? I do not want to go fuel injection and feel the 305 is the perfect size for the cj7. Do the years matter with gas mileage? Would the "newer" carbed 305's have better MPG's than the older? Thanks

[jaredts]

Jaredts, 11 city, 15 highway, why do you say that. I mean, is that from expierience?

My answer was a cross between an educated guess and a little experience.  I've owned several cars with 305's.  Never had a truck with one.  The numbers I posted are about 1 or 2 mpg's less than what I generally got from 305's with a quadrajet in a heavy old car.  My '87 camaro got closer to 18 or 19 hwy, but they are light and it had overdrive.  Go to tbi and my '89 caprice got a little over 20 hwy. and that's a big heavy car.  If you have a 4x4 and you're expecting better than 15 hwy on a carb'ed v8 I think you'll be disappointed.  The inline 6's usually do produce a little better economy, despite having to work pretty hard.  Oh, and years aren't going to matter much.  There are differences in heads and cams, but I'm assuming you're not going with anything too out there (rv cams and such).

[jaredts]

Woops!  I missed the TH400 part (assumed TH350).  Knock 1mpg off my estimate.  Get a 700R4 if you're concerned with economy.

[Grover 1]

I agree with Jaredts.  If you get 15 in town, let me know how you got it.  I get 10 town 14 hiway with my 305.

[VileZambonie]

If your main concern here is fuel mileage your set up is going in the wrong direction. Your 6 cyl will get better fuel economy, an overdrive trans will give you better fuel economy and EFI will give you better fuel economy. What is your goal with this vehicle? What are you going to use it for?

[Captkaos]

I get 17/22 with my R10 305TBI/700R4...

[cherrycj7]

Thanks for the replies. This jeep is going to be my daily driver and weekend trail rig. I was hoping for more power and have wanted a V-8. But mileage realistically is a concern. What would the MPG thoughts be on a TBI 305 engine?? I really want to have a v-8 that gets better than my I-6 is getting and close to 15 city. I realy want a carb for its simplicity but have heard that the chevu TBI system is pretty simple as well. What are your thoughts on this. Is the 305 the right way to go with a V-8? Thanks for all of your imput.

[Stewart G Griffin]

The other factor is how much money do you have budgeted to spend initially?

[cherrycj7]

For the engine, headers, possible need of a rebuild, adapter to the AMC TH400 and engine mounts i have about 1000 dollars figured for it.

[Stewart G Griffin]

i'll get back to you on that.