Prelude - maintenance up to date. In my quest for better MPG I changed everything spark plugs, wire, air filter, fuel filter, all new fluids, pvc, etc. Everything I could think of.
Here’s my story.
Awhile ago my alternator died.. No charge, then the battery died. I bought 2 new batteries and drove home. Each battery lasted about 50 miles (w/o lights or radio on). I got about 12 MPG. Previous to this I was getting really bad gas mileage, maybe 14 MPG.
On the way home I stopped by the junk yard (same day). They had a 1998 4runner with 200k+ miles on it with an alternator. I picked that up for cheap and installed it and it worked ok. The volts were barely above 14, with the lights on, maybe 13.5. But surprisingly with no other change my MPG were back up to 17.5 and I was happy. I drove about 800 miles this way.
Then I was worried about the junkyard alternator, so I searched for a new alternator. I couldn’t decided cs-144 upgrade, napa new, remanufactured, etc. I decided I wanted more amps, not sure why, and a denso. I found a 130 amp 3.4 remanufactured denso on ebay for (seller:starters-alternators) for $104, which seemed to cover all my bases. After installing it, my volts have been 14+ most of the time (seems like heat affects my volts which makes me think I need to do the big 3 mod, anyway) . Now my MPG is up to 18.5! That’s with me driving like a madman, no babying. I bet I could hit 22 MPG driving slow. I double checked this with the ultra-gauge and simple fill up/miles calculation. I can almost hit 270 before the fuel light turns on. These results are from about 800 miles.
I’m not really sure how this works. I spun all three alternators and they all spun fine, so I don’t think it’s a drag problem. The only major variable here is weather between 17.5 MPG and 18.5MPG. Otherwise, I do the same drive 40% city/60% hwy. Maybe the sparks are getting more power?
Just an idea if you’re getting really bad gas mileage and can’t find anything else to change.
TL DR - got 18.5 MPG after changing my alternator.
Here’s my story.
Awhile ago my alternator died.. No charge, then the battery died. I bought 2 new batteries and drove home. Each battery lasted about 50 miles (w/o lights or radio on). I got about 12 MPG. Previous to this I was getting really bad gas mileage, maybe 14 MPG.
On the way home I stopped by the junk yard (same day). They had a 1998 4runner with 200k+ miles on it with an alternator. I picked that up for cheap and installed it and it worked ok. The volts were barely above 14, with the lights on, maybe 13.5. But surprisingly with no other change my MPG were back up to 17.5 and I was happy. I drove about 800 miles this way.
Then I was worried about the junkyard alternator, so I searched for a new alternator. I couldn’t decided cs-144 upgrade, napa new, remanufactured, etc. I decided I wanted more amps, not sure why, and a denso. I found a 130 amp 3.4 remanufactured denso on ebay for (seller:starters-alternators) for $104, which seemed to cover all my bases. After installing it, my volts have been 14+ most of the time (seems like heat affects my volts which makes me think I need to do the big 3 mod, anyway) . Now my MPG is up to 18.5! That’s with me driving like a madman, no babying. I bet I could hit 22 MPG driving slow. I double checked this with the ultra-gauge and simple fill up/miles calculation. I can almost hit 270 before the fuel light turns on. These results are from about 800 miles.
I’m not really sure how this works. I spun all three alternators and they all spun fine, so I don’t think it’s a drag problem. The only major variable here is weather between 17.5 MPG and 18.5MPG. Otherwise, I do the same drive 40% city/60% hwy. Maybe the sparks are getting more power?
Just an idea if you’re getting really bad gas mileage and can’t find anything else to change.
TL DR - got 18.5 MPG after changing my alternator.
