05-24-2019, 10:37 PM
Join Date: May 2012
Location: Vancouver BC, Canada
I honestly have no idea what the MPG are.
My odometer and speedometer are woefully inaccurate despite an attempt to try and bring things back in proper line.
Really, My MPG is more than likely irrelevant to you as each Samurai is kind of set up differently. Thinking of lift, tire size and transmission options (There is a certain year where Suzuki switched from/to a taller 5th gear) and driving habits.
What I can say is that my fuel consumption dropped dramatically after installing the diesel. The drive-ability off road also improved significantly.
Minor hills where the gas engine would fall flat on it's face and have to shove it into first, the diesel could easily take in 2nd or third.
I have jeep YJ springs, and 225/75R15 tires. The jeep YJ springs provide for about 2-2.5" lift. While you may be able to install the diesel without a lift, you won't be able to use an unmodified VW oil pan. 2-2.5" lift is the minimum you'd want to clear the stock VW pan. Even then, you'll want to modify it a little to relocate the existing drain bung to the flywheel side of the pan. and to clear the front differential.
The 1.6TD likes to rev higher than the 1.9TD. It did seem to be a little happier with my higher RPM setup (with my smaller tires) than the current 1.9TD at highway speeds. it didn't have the same low end grunt that the 1.9TD does have though. If you are running larger tires than 235/75R15 I'd consider the 1.9TD.
The "problem" with simply bolting larger tires to gain a lower highway RPM also means a faster first gear for off road applications. Bolt on larger tires with stock gearing and suddenly first gear moves the vehicle like second gear with stock size tires.
One then can't move slow enough for some of those more "delicate" operations where crawling slow is more desirable.
On paper, the RPM is close to identical between an '87 jetta with the 1.6TD running stock tires and an '87 samurai with stock gearing and running 31" tires.
I did find that the 31" tires and the 1.6TD seamed to be a bit of a dog. It wouldn't pull hills as well as would be expected. The samurai has the aerodynamics of a brick and I expect it took a bit more torque to turn those larger tires at freeway speed than it did in the jetta.
I never did try the 31" tires with the 1.9TD.
My poor 1.6TD was swapped out because it wasn't feeling that well. Oil dribbling out of #4 exhaust port (after sitting, not while running) and I expect marginal compression although I have never checked it with a gauge. (screwed on a "rebuild" by Gordon's VW in Langley)