The Blazer S-10 1992 4.3l has a broken gas guage so we are trying to estimate from the odometer.
I'm curios if someone has a rough guess on how much fuel might be consumed during warm up on cold days?

Right now it's an average of 10 deg everyday, has been for 2 weeks. Due to an issue of hesitation the truck has to warm up for about ten minutes before you can head out.

It's roughly about -1-1/2 hr of idle time per tank full.

Reason I ask is because my mpg estimate was way, way off from what I though it should be, but I'm thinking
the warm up time played a bigger role than I may have thought.

 

Sounds like you should spend some time figuring out why you have to let it warm-up for 10min. That is way to long for my tastes. A lot of fuel use at idle would be determined by your method used to deliver the fuel to the cylinders ie: TBI, CPI or Carburetor. Then how large the jets are for the carburetor and the size of the injectors and spray volume for the other two systems.

If you have a way to read Diagnostic Trouble Codes (DTC) I would have that done. Since your truck is OBDI then you would either have to go to the dealer which can cost or find someone with a scanner system that can read your codes. This will help to determine what system on the truck maybe causing you to need to warm-up for 10min.

Could be something as simple as a stuck t-stat or more complicated. Scanning the computer would tell more...

 

Well 10 min is somewhat a gross exageration to the point
10 degrees ,no garage, I have to deal with the issue right now.
When it warms up a bit, I'll tackle my issues.

Gonna get a scanner with my tax cut, until then I'm just going estimate from where it ran out last night.
couldn't possibly get worse considering.

thanks

 

My old Lumina was ODB1, check the book to see if it's got a list of CEL codes, because you might be able to jumper some pins on the diagnostic port, and the CEL or SES light will flash in patterns and tell you if there's anything going on. Mine would have some codes in it, even when the light itself wasn't on...