Hi
I have 1989 4wd Blazer Silverado with a 350 TBI and I love everything about it, except it's thirst! I drive 90% countryroads, mostly on cruise at 55 mph/ 90 kmh, not many hills. I get, at best, 16 mpg/1,5 L/Km, but average 13 mpg/1,8 L/km.
Is this normal for this model?
I have changed the thermostat, with no change in fuel consumption.

What else is there to do?
What regulators, mechanic, elctric or otherwise can I check?

 

MPG Improvement[/b]

Run tire pressure 3-4 psi over std.

Change all drive line systems to synthetic oils

Add K&N air filter or one similar for better air flow

Give it a complete tune up using all AC Delco parts

Add 1 can of seafoam fuel cleaner to tank on the next two fillups.

Change fuel brands, some say it does make a difference, try shell, mobil, etc: alcohol in fuel will hurt your mileage.

Drive it like your sainted grandmother would drive it, slow starts, no run and gun.

For every 5 mph over 55 mph you start losing about 1 mpg.

It takes fuel to move heavy iron, it takes even more fuel to move heavy iron fast.

Good luck and stay safe,

I am seeing more seat time on my motorcycle.

 

Yes.

 

Check your differential ratio, 342s are optimum for highway mileage, but cost 1500. to 2000.$ to change. Also, if you change from higher ratios, your towing,offroad, and low-end/hi-torque will be greatly reduced. If it's not hauling trailers, and mostly on the highway, this gear change couild help you.

 

Run tire pressure 3-4 psi over std. Check, donne that.

Change all drive line systems to synthetic oils. Check.

Add K&N air filter or one similar for better air flow. I,.. consider it.

Give it a complete tune up using all AC Delco parts. How complete is a complete tune up?

Add 1 can of seafoam fuel cleaner to tank on the next two fillups. Check.

Change fuel brands, some say it does make a difference, try shell, mobil, etc: alcohol in fuel will hurt your mileage. Check.

Drive it like your sainted grandmother would drive it, slow starts, no run and gun. Almost check here.

For every 5 mph over 55 mph you start losing about 1 mpg. Check.

It takes fuel to move heavy iron, it takes even more fuel to move heavy iron fast. Check.


6.5 out of the suggested 9 adjustments are already in place and that has given me the result I started my question with.

Perhaps I am looking for a miracle?

Changing the ratio for 2000$ ? No, that would set me back half the money I paid for the ride.
Maybe gasoline is finally starting to be priced at the high level of appreciation that I hold for it? I won't cut down on driving. I'll just make sure I enjoy the luxury of doing so, a bit more.

And if I come up with a radically better way of enjoying V8 performance with lesser gas bills, I'll let you know!