Talk me into a TDI vs. an OM617

I've been debating furiously whether to go with a 1.9 TDI or a Benz OM617.95x for a swap into a Toyota truck. To make such a decision, I normally go with a combination of hard facts and gut feeling, but a lot of the facts are a wash and the gut feeling is being indecisive.

The TDI would get an mTDI conversion and run at stock power levels (or just a little turned up to match the Benz). Reliability is the name of the game here - this is roadtrip/camping/expedition rig that I want to last me a very long time under varying, possibly demanding (cold, dirty, remote) conditions.

The other consideration is fuel economy: the TDI is absolutely more efficient, and weighs nearly 200 pounds less, further improving city fuel economy as well as handling and tire wear. I can swallow the initial cost of the engine, and (grudgingly) live with its timing belt. Incompatibility with veggie oil is a minor drawback but not a dealbreaker.

I've asked Benz-biased owners for their take - their trump card is the OM's formidable reliability record as one of the longest-running car engines ever made, installed in vehicles closer to my rig's weight than the average Golf or Jetta. Yeah, I know they've started putting TDI's in the Amarok and whatnot, but we have yet to see how long those last when used like trucks. I like that they're cheap and plentiful and will run on SVO/WVO. I don't like their physical size and their increased fuel consumption - I expect 22-27mpg with the OM, and 25-32 with the TDI, pushing a 2-ton 4x4 box.

So VW-biased owners, what say you?

I'm sorry no one ever responded to you. I have the same question. I have a 4runner with om617 that is almost out of the shop. I'm so excited to test it out.

I'm looking to do another swap into a Toyota pickup, and have the same question. I have several TDIs and love the cars. I just struggle to think that a 1.9 would be better than a 3.0, even though they claim it can make more power.

I need to learn more about converting it to an mTDI as the wiring is what scares me the most about using an ALH.

What did you end up doing?

That's awesome, congrats! I doubt you'll hear from the OP as his last activity here was 7 years ago. I'd try something new with a tdi swap on the next one.

As far as running a VW 1.9 TDI ALH on vegetable oil, I have run mine on straight vegetable oil for over 30k miles personally with no issues.

The previous owner was a friend of mine and covered over 20-30k with it running purely on vegetable oil, with a small amount of gas/petrol in during cold weather to aid cold starts, and sometimes a little diesel if it was sub zero to aid in preventing gelling.

I would go for the ALH / old TDi in these situations.


Regarding your loom, it should be relatively simple to run it standalone for another vehicle, I know there's a company on here that make standalone harnesses for the ALH and similar EDC15 engines, so it might be worth checking that out. It's also much easier to get high fuel economy out of an ALH with an ECU, due to the wide array of tuning that can take place vs a purely mechanical setup.