Fuel Economy & Improving MPG

[Brewtus]

Hello everyone!


I am interested in what you get for fuel economy with your van(s). I look forward to comparing numbers together and I hope this thread will serve as a resource to pool information and ideas together.

If you'd like to contribute, please list:
1.) Average Fuel Economy (MPG)
2.) Year, Model, & Engine Size
3.) Modifications Impacting Fuel Economy
4.) Other Relevant Ideas & Experiences Improving Fuel Economy


~Dylan

[Brewtus]

I will start out with listing the info on Brewtus:

1.) 16.2 MPG
2.) 1986 Astro Aerolite & 4.3L V6 TBI
3.) Removing excess weight (pending resulting MPG), removed roof-top attachments, and increased tire pressure.
4.) Taurus electric-fan swap, removal of A/C compressor and associated pulleys, and possibly adding hinged side-skirts for long-distance road trips.

[chevymaher]

94 safari 4.3 it gets what it is supposed to. 18 city and 23 freeway.

[xit]

I have kept fuel records for many years on my astro, if I see a major drop in mileage, I know something needs attention If I average all the data over the years it would be right at 18mpg, highway and city. The milage is not too bad considering the age of the van & it is a box. Keeping my speed close to or lower than posted limit is the biggest factor in my mileage.

[90safari]

My 88 Astro gets 16-18 in the city, and 22 out on the highway. A lot of that is the rear gearing. I only say that, as my wife's 90 GMC Safari would get 14-15 around town, and 18 out on the highway.

[Brewtus]

I have kept fuel records for many years on my astro, if I see a major drop in mileage, I know something needs attention If I average all the data over the years it would be right at 18mpg, highway and city. The milage is not too bad considering the age of the van & it is a box. Keeping my speed close to or lower than posted limit is the biggest factor in my mileage.

If you're open to sharing, what have been some system issues you've encountered which have led to decreases in mileage? 18 MPG seems like a good spot to be, especially with an AWD. I admire your willingness to slow down to improve fuel economy! I have read slowing down by 5 MPH can have a quite significant impact.

~Dylan

[Brewtus]

My 88 Astro gets 16-18 in the city, and 22 out on the highway. A lot of that is the rear gearing. I only say that, as my wife's 90 GMC Safari would get 14-15 around town, and 18 out on the highway.

Thank you for sharing! Do you know the difference in rear gearing between the two vans? I have read the longer the gears, the less power and higher mpg. I am interested in figuring out my gearing ratio.

[Mmusicman]

Don't be fooled! Changing your gearing either direction may move you out of the engine's "sweep spot".. the rpm range where it runs most efficiently AND effectively. Lower RPM (too low under the same load) often means MORE throttle (to maintain speed).. since it takes the same amount of HP to move you down the road regardless of rpm. I know.. been there done that. Often times heavier vehicles (with increased loads) may actually improve mileage with more/correct gear (up to a certain speed). It really depends on how hard you have to ride the throttle to maintain your desired speed.

Slowing down (from higher highway speeds) usually will affect mileage.. mostly due to decreased wind load and tire resistance. I can get 18mpg (at slower speeds than I am uncomfortable with). Above 70 the mileage starts taking a harder dive (also depending on wind direction).. I've charted it all. I prefer however, to move with the flow and get there.

I improved the mileage in my 92 by replacing the weak and worn V6 with a fresh V8 more suited to moving a van.

There is NO one answer fits all

[M_a_t_t]

Hello everyone!


I am interested in what you get for fuel economy with your van(s). I look forward to comparing numbers together and I hope this thread will serve as a resource to pool information and ideas together.

If you'd like to contribute, please list:
1.) Average Fuel Economy (MPG)
2.) Year, Model, & Engine Size
3.) Modifications Impacting Fuel Economy
4.) Other Relevant Ideas & Experiences Improving Fuel Economy


~Dylan

1. ~18
2. 95 2wd 4.3
3. E-fan, smooth wheel covers, MPGuino (not sure on tbi, but spider injection needs adapter module to use)
4. Biggest thing you can do is adjust how you drive and get some instrumentation. Aerodynamics is the killer for you. Check out ecomodder.com if you want some ideas.

It might sound farfetched, but my best trip (single drive not a tank) was 24 mpg. That was a very rare occurance though. No traffic and I hit all green lights. This required coasting and timing the lights to get. Engine was already warm as well.

I have since put a v8 in my van. Now I have adopted the "smiles per gallon" montra

x2 that nothing applies the same to each vehicle.

[Brewtus]

Don't be fooled! Changing your gearing either direction may move you out of the engine's "sweep spot".. the rpm range where it runs most efficiently AND effectively. Lower RPM (too low under the same load) often means MORE throttle (to maintain speed).. since it takes the same amount of HP to move you down the road regardless of rpm. I know.. been there done that. Often times heavier vehicles (with increased loads) may actually improve mileage with more/correct gear (up to a certain speed). It really depends on how hard you have to ride the throttle to maintain your desired speed. Slowing down (from higher highway speeds) usually will affect mileage.. mostly due to decreased wind load and tire resistance. I can get 18mpg (at slower speeds than I am uncomfortable with). Above 70 the mileage starts taking a harder dive (also depending on wind direction).. I've charted it all. I prefer however, to move with the flow and get there. I improved the mileage in my 92 by replacing the weak and worn V6 with a fresh V8 more suited to moving a van. There is NO one answer fits all

Thanks for your info on gearing! The load of the build is being reduced substantially (-1,800 lbs and counting), which is where my hopes for lower gearing would come in. I don't mind not maintaining speed as consistently to reduce fuel consumption (the drawback of lower gearing), meaning I won't be pushing the pedal any harder in attempt to maintain speed. But in the end, I doubt I'll end up changing the gearing, anyway. What size V6 did you have and what size is the V8? I like hearing about your improvement with the swap!

[Brewtus]

1. ~18
2. 95 2wd 4.3
3. E-fan, smooth wheel covers, MPGuino (not sure on tbi, but spider injection needs adapter module to use)
4. Biggest thing you can do is adjust how you drive and get some instrumentation. Aerodynamics is the killer for you. Check out ecomodder.com if you want some ideas.

It might sound farfetched, but my best trip (single drive not a tank) was 24 mpg. That was a very rare occurance though. No traffic and I hit all green lights. This required coasting and timing the lights to get. Engine was already warm as well.

I have since put a v8 in my van. Now I have adopted the "smiles per gallon" montra

x2 that nothing applies the same to each vehicle.

I dig the mods you've done! How long ago did you find your MPGuino and do you know of anyone still selling them? What type or style of e-fan do you have? Adjustment of driving style is definitely an important aspect, especially with Brewtus haha. I am hoping to get either an MPGuino or SuperMID but have been unable to find a seller yet. I am a fan of ecomodder.com and will definitely be referring to the info on their site throughout the build. 24 MPG sounds great! Lights are such a killer of fuel economy... Your "smiles per gallon" montra is funny haha.

[M_a_t_t]

I dig the mods you've done! How long ago did you find your MPGuino and do you know of anyone still selling them? What type or style of e-fan do you have? Adjustment of driving style is definitely an important aspect, especially with Brewtus haha. I am hoping to get either an MPGuino or SuperMID but have been unable to find a seller yet. I am a fan of ecomodder.com and will definitely be referring to the info on their site throughout the build. 24 MPG sounds great! Lights are such a killer of fuel economy... Your "smiles per gallon" montra is funny haha.

I bought it back around 2016. I bought mine through this seller, ( http://mpguino.wiseman.ee/eng ) but it looks like he has closed up shop. There is a schematic for building one on the mpguino wiki page ( https://ecomodder.com/wiki/MPGuino ) if you can follow it. The code is available (should be) for download so you just have to wire it up. If not I have an older version of the code on a google doc you can copy and paste in.

I bought the red fans that everyone on here doesn't like. I can't say I would recommend them either, as I don't think mine have been working. I haven't looked into it yet to figure out if there was an installation issue or poor quality.

The smiles per gallon is from MMusicMan (aka 3M). Who was very helpful with advice for my swap. If you are thinking about the v8 swap you will more than likely find his threads about his. Very helpful and pictures are great.

[AstroWill]

"smiles per gallon"

You can even get your own sticker, they also have t-shirts, keychains, etc. https://amzn.to/351UdQ0

[Brewtus]

I bought it back around 2016. I bought mine through this seller, ( http://mpguino.wiseman.ee/eng ) but it looks like he has closed up shop. There is a schematic for building one on the mpguino wiki page ( https://ecomodder.com/wiki/MPGuino ) if you can follow it. The code is available (should be) for download so you just have to wire it up. If not I have an older version of the code on a google doc you can copy and paste in. I bought the red fans that everyone on here doesn't like. I can't say I would recommend them either, as I don't think mine have been working. I haven't looked into it yet to figure out if there was an installation issue or poor quality.

Thank you for the info on the MPGuino! I see a lot of fiddling with building one in my near future. If I need the old code, I will be sure to message you and thank you for the offer. I imagine a some frustration accompanies your fan issues. I have a taurus fan on my S-10 and am hoping to swap the same system into Brewtus.

~Dylan

[AstroWill]

I saved some of what I could find https://sites.google.com/site/astrosafa ... ne/mpguino

[Brewtus]

I saved some of what I could find https://sites.google.com/site/astrosafa ... ne/mpguino

Thank you, Will!

[90safari]

My 88 Astro gets 16-18 in the city, and 22 out on the highway. A lot of that is the rear gearing. I only say that, as my wife's 90 GMC Safari would get 14-15 around town, and 18 out on the highway.

Thank you for sharing! Do you know the difference in rear gearing between the two vans? I have read the longer the gears, the less power and higher mpg. I am interested in figuring out my gearing ratio.

I think if I remember right the 88 Astro has a 3.08:1 in it, versus the 3.42:1 in the 90 GMC. Both were running 245-60-15's, but the 88 got new tires recently and are now 255-60-15's or 265-60-15's. I can't remember which as I've slept since I put them on.

[jeff1]

I have a '94 short safari RWD, fuel system is TBI. I have owned the vehicle since 1999 it now has ~342,000 miles on it. I consistently got 18 MPG in the summer and 16 MPG winter. this is a mix of city and highway. A couple years ago had to rebuild the distributor. At that time I advanced the timing approximately 2 degrees beyond spec. I now consistently get 18 mpg winter and 20 MPG summer. No other changes were made well unless you count the fact that it is on the Minnesota weight reduction program otherwise known as rust.

[MechBob]

Good stuff,here. Have to go by memory, for some of this. Winter van,94AWD, hi-lo t/case, runs M&S studded tires, also has full time locker. Hard to judge mileage, as have to warm it up before going up and out of driveway, but on trips i took before, lucky to get 12. Biggest reason is the aggressive M&S tires, they cause lots of wind resistance.Summer van,96AWD with full time rear locker, but running mild yokohama snow tires, generally get 16, no matter what.Actually, last summer, on one of my trips, averaged almost 17, 80mph, in all the wind in WY. Some years ago, when i got the summer van, it had highway tires, and, going through Saskatchewan, where the speed limit is very much lower, got almost 22mpg. Tires can be a killer.