Just made another trip, it was 155 miles all highway (55mph). I got 24 miles per gallon. These numbers are just getting better! :c) I put it in the gas log. I'm missing some receipts from when I last posted on here. When I locate those, I'll put those up.

I never thought I would be able to get these numbers before just from fixing my EGR valve!

Now, I'm wondering if I put the Aero-mods back on, I can get even better ... 30mpg?? I guess we'll see once the snow melts, as that's the next time I plan to be on the highway for a long distance.

I figured it should be hard to turn, as it's a pump. The power steering pump is hard to turn as well. Not HARD hard, but you have to put effort into it, unlike the alternator and idler pulleys.

And, Still no squealing since I put that Lucas Power Steering Stop-Leak (Seal Conditioner and renews Rack and Pinion). No leak either. It chirps a little when the engine is cold, but not the really loud squealing like before.

30mpg from an automatic SUV rated 15 combined? 24 at 55mph is a miracle.

Yea, I can hardly believe it myself.
The highway estimate is 18mpg, even before any mods I got 19mpg going 55-60mph, but 17-18mpg going 70mph.
From everything I read, fixing the EGR valve shouldn't have done THAT much for fuel economy on the highway. I don't know if it's because it's functioning correctly now, or if it's because my check-engine light is no-longer on because it's fixed.

I really have no clue about the accuracy of this statement: I read somewhere that when your "check engine" light is on, your car's computer goes into a default mode and doesn't really pay much attention to the sensors, and gas consumption is higher (basically the default mode when you reset the computer??)
Anyone else hear of this? It would make sense... but I really don't know what the "check engine" light being on does, other than tell you something isn't working.

Some (maybe an old one like yours) might do that, but I think most only go into "limp-home" mode if there's something seriously wrong that could damage the car, rather than any time it throws a code.

At least with the older models, like my Buick, when the Check Engine light is on, the car defaulted to a "limp home" mode, and ignored the sensors. Newer models may take some sensor readings, but I'm not sure.

If you aren't sure, you can find out easily enough. Get/borrow a GPS, and get it to show your speed. Go for a drive, and when you are at cruising speed (the higher the more accurate) look at your speedometer reading, and then the GPS speed reading. If they are the same, the miles part of your MPG is accurate.

If the speeds are not the same, divide the GPS speed by the speedometer speed, subtract one, multiply by 100, and you should get the percent difference.

I'll use my Jeep for an example. I knew that I was going faster than it said, so I got a GPS, and when my Jeep said 45 MPH the GPS said 55. There you go.

55/45=1.22
1.22-1=.22
.22*100= 22% farther than logged miles.

The reason that you (and I) care is that the odometer will read fewer miles than actual. That means you could be getting better MPG than you know.

Again, my Jeep for an example.
The last time I filled up, I used 14.8 gallons. My odometer reading was 200,464, and the previous reading was 200,205. Subtract the two to get logged miles since last fillup:

200464-200205=259

If I was to take 259 miles/14.8 gallons, that would be 17.5 MPG. Not pretty.

But because I actually move 22% farther, I am moving 259*1.22, or 316 miles.

So I am actually getting 316 Miles/14.8 Gal, or 21.4 MPG (still not pretty, but better)


If you don't have a GPS, you can use mile markers on the side of the road. Next time you get on the highway, drive until you pass 10 or so mile markers, and compare that with the number of miles on your trip meter. Then divide the number of mile markers by the number on the trip meter.

Also, in place of the GPS, you could have a friend with a car (with a speedometer that is known to be accurate) drive alongside you, and divide his speed by your speed.


Wow, I think this is my biggest post yet :D Hope it makes sense/helps

Awesome post!
... It makes me wonder, though, because on my Buick the speedometer shows I'm going faster than what I actually am - it'll say I'm going 55, and the gps will say I'm going 53 or something to that effect. It's always done this, even after new tires. The Explorer seems fairly accurate, just maybe 1mph off or so. Though, I haven't tested it in some time (and not with the more air in the tires)

If anyone is interested, I am putting my Explorer up for sale. It's an unfortunate ending to this thread as I've had fun and enjoyed tinkering with it. The main reason I had it was because of it's 4 wheel drive, but now that it's broken it does me no good. I can't afford to fix it, so I'm cutting my losses. If you're interested at all, take a gander at my eBay classified listing and/or Craigslist posting below:

eBay

Craigslist

Thanks everyone for all of your input, help and comments on this thread! I appreciate it.