Fuel Efficient Station Wagons

My Volvo V-40 wagon with the 1.9 Litre & 5 speed auto shifter does really well... I am averaging around 30 mpg driving to & from work (125 miles a day-mostly Interstate). I don't push her too hard 55-60 mph.
(Results vary- especially if I start putting my foot to the pedal )

 

IIRC the Dasher Diesel got in the high forties.

mike

 

Fuel efficient wagons....

My 1985 VW Quantum w/ 1.8L 4 cylinder and a 5 speed gets about 34-35 mpg on the highway (65-70 mph), and about 24-25 mpg in town/short trips. I converted it from F.I. to a Weber 32/36 carb set up. Hope to achieve more mpg by re-jetting it, and making some further adjustment to the timing. Still a bit on the slouchy side as far as performance goes. David.

 

Zetec and Duratec motors can be mated to a T5 transmission. I would think they could also be adapted to something like an AOD or a C4 for use in a larger older wagon.

I have another small engine big wagon project idea, it involves the 200hp 3.4L V6 from a Camaro and a 5-speed stick in a 77-79 Impala wagon. Another V6 idea involves the 200hp 3.8L Mustang V6 engine in like a Torino/Montego wagon or even a 83-87 Country Squire. I also can't wait to see what can be done with the 365hp 3.5L EcoBoost V6's in the late model F150s when they get older.

 

@Occupant: Don't forget that the most important part of economy is the torque curve. You need it to peak low in the revs to be able to gear for economy and keep reasonable performance. Those V-6 engines are alright, but for real economy you need the rear end to be 2.73 or steeper. The idea is to have the revs on the highway no higher than 1,500.

 

With the V6 the axle ratio needs to be a wee bit shorter. They don't have the down low torque of the V8's and it would be shifting constantly in and out of overdrive if it's cruising too low. The piston sweet spot formula is what I use to determine if an engine is running at maximum efficiency by determining if the piston speed falls within a certain range. It varies according to the stroke. You want the pistons to be traveling between 16.4m/s and 19.8m/s. For the Essex 3.8L engine (and GM 3.8 V6's) this is between 1740 and 2100rpm (3.39 inch stroke). So for my car with the 2.75 rear end and the 205/75R14 tires (26.11" diameter) and the FMX automatic that low end sweet spot for 1740rpm is 49mph. With an AOD automatic it jumps to 70mph. The high end comes to 59mph with the FMX and 84mph with the AOD. To drop that down to where the high end is at 77mph and the low end at 64-65mph I could use a 3.00 axle ratio and not change the tire size at all. 3.00 would be the ideal ratio to have with the V6.

The slightly longer stroke of the 351C engine in there now means I need 1686 to 2086rpm. With the FMX and 2.75 and 26.11 inch tires, that means my ideal cruising speed with this engine is only 47 to 59mph, which makes sense with the 55mph national speed limit after 1973. With an AOD and no other changes, my cruising "sweet spot" moves up to 68 to 84mph. That actually makes sense to me, because freeway speed limits around here are either 70 or 75. If I was in Ohio I'd consider using a 3.00 axle with the Cleveland and an AOD. Of course if I need to cruise at 50mph to 55mph I could always drop out of overdrive into "D" and until I get over 60-65mph I don't NEED the overdrive! On flat land I could use it, sure, but even with moderate rolling hills it would probably be worth staying in "D" and certainly with more than just me and some fuel in the car I wouldn't want overdrive until I was well into that 68-84mph range to avoid lugging the engine.

 

M.p.g.

Wagonette has a stock bore stock stroke 89 318.Factory 390 lift roller cam,Edelbrock SP2P intake ,electronic ignition with high output coil,small cfm thermoquad {750} Late 70's mopar 3 speed with overdrive manual trans,2:76 open rear with 225 70 14 tires.tuned fenderwell headers with ceramic OBDII compliant cat converters,cold air scoop and gets a realistic 24 highway [@70 mph] and 10-14 in town. It turns 2000 rpm at 70 mph.would love to bring the rpm's down a little more ,but thats the tallest gear for the 8.75 diff.

 

It's not a wagon, But similar so perhaps it'll be inspiring; Between my Father and I driving his 2000 Dodge Caravan (3.0 Litre V6) We've managed 25 MPG for a few fillups, And I did mod the car a bit. I don't know what we've gotten lately as we haven't had complete fillups.

As the van is now, We have pizza pans on three of the four hubcaps (One fell off and I saw it about to come off before it did, I may have had the choice to re-attach it too as I was stopped then) and we removed the roof-racks and bug deflector. There are more mods that could be done too, But we haven't done them.

We use a ScanGauge II (It hooks up to the OBD-II port) to monitor things like the RPM, Current estimated fuel economy and current estimated fuel economy average.

 

I think converting a full-sized Wagon (1977-1996 years) to Diesel would allow 30 MPG HWY easily. Yes Diesel is pricier than gasoline and Diesel engines (Or some of them, Anyway) can be run on vegetable oil (But I suggest reading about it first before doing it) which I like the idea of.

 

Some GM wagons came with diesels ('78 thru '85).

My '82 Custom Cruiser is a diesel. 2.93 axle ratio, 2004R trans, 24MPG urban/city and 29MPG highway. I run it with percentages of vegtable oil ranging from 10% to 35% depending on ambient temps.

While the '82 was very good in it's day, my '92 Custom Cruiser (350 TBI, 700R4, 3:23 ratio) gets 18 urban/city and 23 highway (so far but I think it's capable of better hwy mileage) with twice the power and 10 percent cheaper fuel (91 octane ethanol free).

 

And no GoodWretch diesel to contend with. I knew a guy who had a diesel Eldorado and three spare engines; one had new head gaskets, and when the gaskets in the car let go, he'd swap the engines, then redo the head gaskets on the next spare engine. Last I knew he still had it, and that was 6 years ago.

 

I did some in town running but mostly hi way and I am very happy with my Roadmaster getting 24 mpg and that is without trying. I am not setting the cruise or driving 70mph, I am driving the $#*+ out of it and still getting that mileage.

 

I plan to replace the y block/3 speed in my 56 ranchwagon with a 390 fe/vintage overdrive. For improved milage I plan to replace 5/64th piston rings with 1/8 th inch,
rv cam and lifters, quadrajet (little bity primaries), multi spark ignition etc. I would like bearable economy with the ability to rear steer with the right pedal.Just started the fe, and purchased a t85 OD. We will see how it comes together

 

Speaking of decent mileage, my Magnum actually got better than 9L/100km on a trip to Hamilton On and back this past weekend, which is surprising since it normally runs just under 10L/100km.
05 Magnum 3.5 L 42RLE trans.

 

I like the Magnum. I think it is the best looking wagon since the Chevy
Nomad