MK1 MPG build need your input,please reread,I edited my post

[vwsparts.com]

I would like some input from the real builders/drivers/owners of gen 1 rabbits, I used to build VWs but then the purpose was make them faster, Now the goal is mpg. I moved to the country years ago and everywhere I go is 100 miles or more round trip. I know switch to 14's and lrr tires. I have an 83 caddy that does not run, I have several engines and transmissions to pick from, I just want to hear the results of your combinations to help me make my decision. I have several transmissions 4speed, 5 speed,and auto laying in the shop to pick from I have a 1500 a 1600 an 1800 and a 1600d I have zenith 2bbl and manifold,weber 32/36, weber dcoe,84 rabbit 1bbl carter weber, cis and digifant need to balance work involved vs real world drivabilty and mpg. thanks. Actually kinda leaning towards 1600cc, 1bbl, 4speed OD trans

Edit; I have all this stuff laying around want to use some of it up make a low buck beater truck and save a few bucks on gas in the process. I have hyper miled toyotas and festivas I know my basic fuel saving tips and tricks.I am not going to hyper mile this, I am not even going to rebuild these engines or transmissions I saved them because they were good whenI pulled them to save them, might do rings rod brgs and cam swap but really trying to stay low buck stupid/simple.Don't really want to go diesel but it is an option. Please tell me your real life results with similiar components for example I am not going to go to the trouble to swap to Digi if you only picked up 1 mpg when you did your digi swap,etc. . Thanks

[ps2375]

My last Rabbit was getting over 30mpg while cruising at 80-84mph. It made about 95whp at a local dyno. I had a 8:1CR 1.8L w/ the big valve head on it. I had a 4-2-1 header and a Bosal exhaust that was not quite 2" diameter. The "G" grind cam had a better "combined" mpg, but the bigger cam(276 or a 280, I can't remember) did better on the hwy a cruise for mpg. I had the tall ratio 5speed in it w/ 175/70-13 tires. AND it was MegaSquirted so I could dial in more timing at cruise loads/rpms and lean it out there too.

My next motor was going to another 1.8L block w/ 10:1CR and a crossflow head from a mkIII. With a ported mkIV intake manifold, same cam, same tranny same car. Was shooting for 100+whp and better mpg's. Pretty confident it would've delivered, but it was totaled by a dumbass that rear-ended me while I was waiting for traffic to move.

With the 95whp motor, the car could tow our mkIII on a tow dolly no problem, I was never wanting for power/motivation up a long 6% grade I traveled on occasion ( I even passed a fire truck going up that grade, not knowing it was a fire truck going to a vehicle fire). It would start in below freezing temps w/o needing to touch the gas pedal (thanks to a well tuned MS).

[krusher]

Its the same old story when it comes to any engine when it comes to mpg.

1: drive slow 50/60mph to get better mpg.

2: how many $'s do you want to spend on engine mods to have to drive thousands of miles to to get it back in fuel savings?

simple answer is TD engine and 5 speed box
(or gear it so it runs your desired cruise speed at peak TQ is 4th or 5th)

light 15" wheels and low rolling resistance tyres. max pressure 165/60/15

I have a 74 1500 (just putting it back on the road so no real mpg figures yet) but vw brochure says 33.2mpg imp/uk gallon, 50mph 47.8mpg / 60mph 40.2 mpg.

I just put an AEM fuel air ratio gauge in it yesterday as I am interested to see how well the solex carb meters fuel.
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(06:31:07) RoachGhia: "i drink dick way too fast"

[vwjetboat]

put a modern turbo diesel in it.. get more power & 40-50 mpg.. buy a wrecked car... and you set..

[TDCTDI]

Get a '96/97 Passat TDI donor car & swap the driveline from that. That was the last year that would "easily" be adaptable, they had the tallest final drives that were geared for the smaller diameter wheels on the rabbit.

I currently have a 03 ALH TDI with a '97 Passat TDI trans stuffed in my 77 rabbit.
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Everybody born before 1975 has a story, good, bad, or indifferent, about a VW.


GOFUNDYOURSELF, quit asking everyone to do it for you!


An air cooled VW will make you a hoarder.


Do something, anything, to your project every day, and you will eventually complete it.

[vwjetboat]

[krusher]

[Butcher]

Maybe I'm missing something, but the poster is looking for 'GAS' mileage and wants to use CIS, carb, or Digifant. I do not see how this is possible using a diesel engine.

I would use the 1500, high compression pistons, Digifant [with a custom chip], and the transmission with the lowest ratio that you have. Skinny tires and remove all the stuff in the car you do not need. Install the rain gutter defectors too.

If were looking for maximum efficiency, then converting it to hybrid.

[vwjetboat]

[vwjetboat]

OK.. btw guys.. ever here of the 101 gas mileage seminar ? i haven't in 35 years .. but it cost 75 bucks.. was a few hrs long got a paperback book with all kinds of instructions and ways to ATOMIZE the gas .. and they even had a big ol Cadillac in parking lot that got like 90 something mpg.. I chit you not.. it was all about heating the gas to a perfect temperature right before it goes down the intake basically as a vapor.. fully atomized ..

I never really tried but one .. heating a copper coil with heater core bypass .. i got worse mileage.. but i was like 18 or 19

[TDCTDI]

[krusher]

[Butcher]

[vwsparts.com]

I didn't want to be the first one to fan the flames on the 100 mpg bigfoot mystery carb. But you can only go so lean, I think around 15:1 and then it is too lean to light ,honda had the cvcc motors so lean they had to have a seperate precombustion chamber and an auxilary intake valve, they would light off a tiny rich mixture in the precombustion chamber and it would light off the too lean to light with a spark plug intake charge. Another factor in too lean,is heat,preignition,and usually a new piston or two, remember your oxy acetelene torch cuts when you throw in the extra 02 some times I would kill the gas altogether and cut with just O2 once my piece was up to temp, Thanks everyone for your input on my project, keep the ideas heading my way one of you just might think of something the rest of us have overlooked!

[ps2375]

Not true, I had my MS tuned for 17:1 to 18:1 in the cruising load range, it needed more timing advance there, but with a good coil (I was using a mkIII coil minus ignitor as I had a MSD box triggering the coil). And these motors have a decent combustion chamber and plenty of cooling for the head. I was also running a euro oilfilter flange w/ built in thermostat that went to (surprisingly) an oil cooler that looked like it came right out of the dog house on an ACVW. And I had also fitted the oil "warmer" from a later VW to help warm the oil in cooler weather.

[vwsparts.com]

[krusher]

[ps2375]

[krusher]

[ps2375]