Tuning engine for more MPG

[Rookie162]

I have a 2002 astro AWD 104k miles which gets me 12-14 MPG

Is a $200 tune from pcmperformance worth it to get mpg outta my van?

Idk what else to do to get more city mpg outta the van.

Thanks in advance

[Corsemoto]

Do they guarantee an improvement in fuel economy?


Waste of money on a vehicle that age where that money could be better spent improving/optimizing what you already have - tune-up, tires/pressures, suspension, brakes, wheel bearings, drivetrain, transmission, fuel system, etc.

My point is, there are probably neglected areas of your van that could stand to see some maintenance. If your van is stock, your mpg seems low and so could likely see an improvement from those areas but wouldn't expect a huge gain in city mpg anyway.

[Lumpy]

Let's do the math...

Currently get 13. Let's say they could bring it up to 16 (I doubt it but let's err in their favor).

Let's say you travel 10k miles per year.

10k miles @ 13 MPG = 769 gallons
10k miles @ 16 MPG = 625 gallons
Difference (fuel saved) = 144 gallons
Gas @ $2/gallon = $288 fuel savings - $200 tune up = $88 fuel savings per year.

As far as believing you'll get better gas mileage...If your van is horribly out of tune now then a tune up will improve things. 13 to 16 MPG is about 23% increase. That's just a bit too far past realistic for me.

If these guys are bring your tune condition back to where it normally should be, that seems like an expensive tune up to me.

If these guys are claiming they can tune something to increase your MPG beyond what a normally, well tuned engine would do, that seems like expensive snake oil to me.

Lighter right foot will increase MPGs better than anything.


Lump

[Mmusicman]

I have a 2002 astro AWD 104k miles which gets me 12-14 MPG

That's about what mine gets... but in part due to age (200K), AWD, tires too tall, and higher than typical wind-load due to lift. My last 2000 RWD cargo got about 17mpg under same conditions.

Fuel economy really varies quite a bit on many variables... speed, weight, height wind-load and headwind, tire size, driving habits, A/C, etc... assuming engine is running correctly. I literally got 18mpg the other day on the highway (doing about 80) headed north, and got 12 coming back. I had a tail wind one direction, and a head wind the other... which was the ONLY difference.

One hard fact, the O2 sensors will typically determine your fuel needs, based on how hard you push the throttle. More throttle means more air coming in, and more fuel needed to correct the ratio. I would assume this will probably almost always apply, regardless of tune.

Now I will say I believe you can "tamper" or "modify" things to "fool" the engine, or take it out of spec. In my case, I improved my fuel mileage ever so slight by disconnecting the IAT (intake air temp) sender... which causes the computer to think it's very cold out. As a result, ironically, it actually richens the fuel mixture, but also increases the cruising timing... which in my case is normally extremely low because I have to push so much throttle to overcome wind-load. This feels stronger, and seems to overcome the wind-drag better. The same scenario may not improve mileage for others under different circumstances. I also found another slight bump by disconnecting my final O2 sensor, which under my current condition of a slight exhaust leak, tells my engine I'm running too lean and to add more fuel. By disconnecting, I'm fooling the engine into thinking I'm at the optimum default level. This gave me about a 0.5mpg bump. If I fix my slight exhaust leak, then this may no longer be beneficial for me.

It typically takes "X" amount of HP to push you down the road... that number does not vary. How you achieve that number happens various ways, and the computer attempts to keep the air/fuel ratio at optimum, regardless.

I believe my engine could benefit running more timing, but I haven't figure out how to do that yet. Maybe a tune could help... I don't know.

I am curious if anyone has had actual success with a re-tune for better mpgs.
I have questions on this subject too!

Good luck.

PS: My V8 gets better fuel economy than my V6.. but I doubt emissions compare.

[Rookie162]

I think ill try a tune up and new O2 sensors for starters.....see how much thatll get me

[dramey]

I would include an air filter, fuel filter, pcv valve, cap, rotor, spark plugs and check the condition of the spark plug wires including their resistance and replace all the vacuum hoses. Before you buy a cap and rotor, test the distributor for excessive movement.

[AstroWill]

Good idea, if you are running on 5cyl I could definitely see a big improvement happening ;)

A RWD shorty cargo weights 1100lbs less then a newer AWD.

[Rookie162]

Thank you for all the great feedback I definitely will get things started tomorrow morning on what to purchase with a tune-up

[97cargocrawler]

Your best tune will be whatever's on the radio after you pull out all the **** you're not using like seats, tools, loose change...

Proper tire inflation is probably the best gain in fuel economy. The light foot thing is forgotten in minutes.

[icebrrg3rd]

...Lighter right foot will increase MPGs better than anything.


Lump

Your best tune will be whatever's on the radio after you pull out all the **** you're not using like seats, tools, loose change...

Proper tire inflation is probably the best gain in fuel economy. The light foot thing is forgotten in minutes.

Yeah, easy on the load pedal is best. And not running 35" swampers...

-Andrew

[Lumpy]

Yeah, easy on the load pedal is best. And not running 35" swampers...

Oh absolutely.

18 MPG with 31s, in town, rarely freeway. But my foot is a lot more arthritic than most's. Imagine what I'd get if I had 24" rubberbands and spinners.

...


Lump

[97cargocrawler]

...Lighter right foot will increase MPGs better than anything.


Lump

Your best tune will be whatever's on the radio after you pull out all the **** you're not using like seats, tools, loose change...

Proper tire inflation is probably the best gain in fuel economy. The light foot thing is forgotten in minutes.

Yeah, easy on the load pedal is best. And not running 35" swampers...

-Andrew

Yeah, but I'm not complaining about my 9mpg. It's better than the 6mpg I was getting in my other ride. I did put helium in the tires and that helped A LOT!

[Meterpig]

Take off the A/C and power steering. Bet it gets 1 to 2 mpg better. And this is a free. So, after like 6 million gallons, you would be making money driving the girl.

Seriously, do all the maintenance stuff (spark plugs will challenge your religion) and then lower it. Put slightly smaller production tires on it from Michelin. Lower the front end an inch and the rear if you can. They should get in the 20's pretty easy. Although, both of mine 15 tops. Now that I have a lift, 11mpg makes me happy.

[Lumpy]

... but I'm not complaining about my 9mpg...

That's an important point. "Complaining" about gas mileage in an Astro is like "Complaining" that your motorcycle carries only two people.

We've got a 1 ton Dodge pickup that gets better MPGs, and that's while towing two horses and a living quarters trailer.


Lump

[Mmusicman]

We've got a 1 ton Dodge pickup that gets better MPGs, and that's while towing two horses and a living quarters trailer.

Nice! That's some fuel-mileage I'd be HAPPY to have, either way!!

[stanvalp]

what about a deteriorating transmission. one that only shows slight failure signs randomly

[AstroWill]

what about a deteriorating transmission. one that only shows slight failure signs randomly

It's on borrowed time, if you care to rebuild it, now is the time.

[stanvalp]

i here you. it's a 2004 and only has 65000km on it. i also recently, discovered the cause of the excessive backlash in the rearend. worn splines between the spider gears and axle shafts. my theory is that the PSW worker who used to drive it, thought the transmission was a brake. i hope she does the same thing to her personal vehichle

[cybrvanr]

Keep in mind guys if you are calculating your MPG's using the odometer, and you change your tire size, you are getting inaccurate mileage calculations. With larger than stock tires, they spin slower at the same speed, thus your speedometer reads lower, and the odometer counts less miles traveled...vice versa for using smaller tires. Use a GPS to count your mileage and then use that for your MPG calculations