Weber Carb

I just had my Weber Carb installed and couldn't be happier with the performance. My only concerns are it seems the gas milage has gone way down - I used to get 15 MPG now it's more like 12 MPG. I remember a post where everyone one talked about their Weber and how they were getting great gas mileage, but I am unable to find the post.

If I remember correctly, some one said they were running a fuel pressure regulator. Where do you get it and how do you put it on? Also I believe someone suggested running a lower thermostat.

I am running a stock rebuilt 258/T5 with stock gearing.

Thanks in advance!

I have the Weber 38, and I'm getting an honest 20 MPG on the highway.
If you have the weber, I would recommend you also do either a "nutter bypass", GM HEI, or TFI ignition mod as well. this combination seems to work really well.
I went ahead and installed the 160 thermostat today. My temp gauge has been erratic since the webber install and the new thermo hasnt helped it. Guess I will start replacing more things.

Bob - do you have any part numbers for what you recommend? Or will the local auto parts place know what I am talking about?

Thanks for the reply.

weber carb

i have a weber 32/36 dgv carb and i get around 20 mpg on the highway, but i believe that to be caused by the 3.73 gears, 32 in tires, and t-5 tranny, this carb was also supposed to increase economy. As to the thermostat i still have the 195 (i believe) and i do have the fuel pressure regulator, but i have been told that it is not necessary or really needed at all, but i could be wrong...


Original Owner
Hey Muger1 which weber do you have?
I have the 38 Outlaw and my mpg did go down.
I'm also using an HEI distributor and 190 thermastat.


SOA Member
Middle of No Where and Too Far From Any Where
check that your settings are on-you may have to increase your idle jets as crazy as that sounds-you can email them at and they should be able to help you-JC:p