Why We Chose Bostig

Let's face it, trying to choose between Vanagon engine conversions is a daunting task your first time around. From the day we decided an engine conversion was our new path, to when we finally put down the money for a Bostig system (or kit), was over two years of investigation and careful contemplation. Hopefully this summary will help shed some light on the topic for you.

Let's start with some quick bullet points and then we'll dive into the details:

Bostig Pros

Bostig Cons

  • Not CA smog legal - Should have no problems in the other 49 states

  • If you want "more power" (very subjective)

  • "Keeping it all VW" (even more subjective)

For us the "Cons" were a non-factor. We don't live in California and the "more power" debate is a highly personal choice. Too much power and you run the risk of damaging your transmission. The Vanagon was never meant to be a high performance road machine. It's a van most people use as a mini-camper, family transporter, and/or recreation vehicle. It gets you from point "A" to point "B". If you're looking to do donuts in the parking lot to show off, you have picked the wrong vehicle entirely. More power eventually becomes a diminishing return with lower gas mileage and higher wear on the transaxle. Bostig hits the sweet spot in our opinion; you get a nice bump in horsepower with no added wear to other major components.

And don't even get me started when people pull the “keeping it all VW” card. This reason comes up with amazing frequency, and is such a load of crap. Sorry. Nothing like basing a huge decision on blind brand loyalty! If you love VW so much then why are you converting your engine in the first place?! Clearly VW nailed it with the woeful Waterboxer, ha. And guess what? Many of the Zetecs used in Bostig conversions were made in Germany. If we're going to use arbitrary reasons, "Made in Germany" is pretty close to VW. Problem solved. I want a reliable Vanagon, period. Apparently others don't as long as they can flaunt their VW badge. Makes no sense. (I think I'll stop right there before I get myself into any more trouble.)


This should be your bottom line. If your engine conversion isn't reliable then what's the point? You might as well save yourself a TON of trouble and stick with the old Waterboxer (WBX). It's nice to see Bostig shares the same point of view as us: Link 1 and Link 2.

Getting stranded 1,200+ miles from home and disrupting a major family vacation was our tipping point. Repairs for our WBX came in anywhere from $3,000 for a rebuild to $8,000+ to have a "new" GoWesty engine installed.

Uh, no thanks.

The WBX is old technology, and wasn't even sufficient when new. When you have modern upgrades available for roughly the same cost, why anyone would dump that kind of money into old tech is beyond us. The OBDII on the Zetec allows for a modern diagnosis with error codes. No more blindly guessing at what's wrong with your outdated engine.

For us the conversion choice came down to Bostig vs. one of the Subaru options. The other options were either too costly, too complicated for our timeframe, too complicated for our skill level, or a combination of all three. Just Google "vanagon breakdowns" or head on over to The Samba and you'll find no shortage of major engine failures. The Waterboxer is the biggest culprit, but next in line are the Subaru conversions. Major issues relating to the Zetec are pretty much non-existent. I literally can't find a topic where someone has been hit with a major Zetec failure. I'm sure someone somewhere has had a problem, but I couldn't locate it. On top of that, if you do have major problems with a Zetec, just buy a whole engine for like $400 bucks and be on your way! That option at that price does not exist with the Waterboxer, Subaru, or any other conversion out there. It just doesn't. One of the most common Subaru conversions is the 2.5L engine, which is an interference-based design. Interference engines greatly increase the chance of catastrophic engine damage in the event of a simple belt failure. By contrast, the Zetec is a non-interference engine. Break a belt? No big deal.

As mentioned above, Waterboxer failures are well documented, but here's a few examples of failed Subarus that really tipped the scale in Bostig's favor:

We've "been there done that" with one vacation basically ruined by the WBX 1,200 miles from home, the last thing we wanted to do was replicate that experience with a costly Subaru conversion.

I know what you're saying, "You cherry-picked those examples!" Well, you're right. But these aren't the only ones, and we have yet to find a single, similar scenario go down with a Bostig conversion. Again, the worst case scenario with the Bostig setup is a blown engine; go pick up another one for a few hundred dollars and you're on your way.

More things to consider:

  • Subarus have a history of failed head gaskets that most people replace during the conversion. Not so on the Zetec. This guy's motor was "rebuilt from scratch" and still blew a gasket after only 30,000 miles. (Weirdly stated as if it's some sort of achievement.) I don't care how hard you drive, that should not happen. Blown Subaru head gaskets are the elephant in the room that no one seems to talk about. It is not normal to replace head gaskets with such frequency! How people overlook this is beyond me. Blind brand loyalty sees no end, apparently.

  • Subarus reuse and modify the old wiring harness from the donor vehicle, Bostig's wiring harness is brand new, which is a big deal to us. (Basically no chance of broken wires or connections.) Just ask this person if they wished their harness would have been brand new:

  • Subarus and Waterboxers are rebuilt, Zetecs aren't. You can even purchase brand new "crate" Zetecs, though they are getting harder and more expensive to obtain. (To be fair, you can buy new crate engines for some of the other conversions too. However, they are even more costly and they still don't come with a new harness.) By using a factory-sealed, reliable engine from the get-go, you will invariably run into less problems. On top of that, you get Bostig's support (see more on this below). Most of the other DIY options leave you on your own searching the internet for answers.

In summary, nothing is ever perfect, but Bostig wins hands-down versus the competition when it comes to reliability.


As mentioned before, we spent over two years looking into conversion options. And guess what? We still don't know what exactly is needed for the Subaru, 1.8T, diesel, etc., conversions. That's obviously a huge problem. For an amateur DIY mechanic Bostig is the only one that had/has clear instructions. Their manual is freely available to anyone and it shows you all of the tools and parts you'll need. This was a big selling point. The other kits on the market just say something like, "Includes easy to use manual." or "Step by step instructions." Well, prove it before I buy it. Bostig did!

Here's a classic example of why anything but a Bostig would not work for us. This is referencing the 1.8T conversion, but we have seen similar quotes for just about all of the conversions (except Bostig):

This person has their own shop and has had trouble figuring things out. To quote:

"I will say this kit is not the easiest thing I have done. The manual is vague in areas and really takes some thought. This conversion is certainly for more advanced mechanics."

That is literally the opposite of what the majority of people are looking for. Even if you are an advanced mechanic, why take on such a complicated build? If the install is complicated, what about when it comes time to repair something? If your conversion is difficult for an "advanced mechanic" to work on, good luck when something needs to be replaced.

Parts Availability

In some areas of the country Subaru parts, dealers, etc., are almost non-existent. On the other hand, the Zetec is very common. This is even more of a problem is you plan to travel outside of the country. We have no plans to travel outside of the USA and Canada, but if we did we would definitely NOT go with a Subaru. As mentioned above, there are several well documented Subaru breakdowns in South America that left people stranded for weeks looking for parts/engines and was very costly. We have to think a Zetec would have faired much better in the same scenario.


In general, with all things considered, any thorough DIY option will run between $6,000 - $10,000. (The exception being the diesel conversions, they were simply too expensive for our budget.) Bostig fits squarely into this window, with most of the cost coming from the kit. Going forward (not to beat a dead horse, but again) worst-case-scenario is that your engine blows up. Another sub-100,000 mile Zetec can be had for a few hundred dollars. Subarus, Waterboxers, and 1.8T replacements can run 10x that cost or more. Even if you don't DIY everything, fixing the Zetec will be cheaper in the long run.

Costly engine repairs and rebuilds will be a thing of the past. Anything beyond a simple / cheap engine repair won't even be considered. You can just pick up a different low-mile engine for a few hundred bucks. Long gone are the days of paying thousands of dollars troubleshooting engine problems.

To be fair, Rocky Mountain Westy now offers a Bostig-style Subaru kit that starts at about half the cost. (A more comparable selection to Bostig rings up just over $4,400.) However, there's no mention of long-term support, custom ECU updates (also called "tunes"), etc., all of which Bostig's kit includes. And look at RMW's options checking out, there are no less than 13 to choose from! Some of these do not have obvious answers and are engine specific, so you better know what you're talking about. In comparison, Bostig only has three very basic questions when checking out. RMW doesn't offer their manual for free like Bostig does, so maybe some of these questions are answered in there. However, this still won't help you during the checkout process, because you obviously don't have their manual yet!

You'll hear people claim you can do a Subaru conversion for $3,000 - $4,000 dollars. (Or even less, ha!) If you basically consider your time worthless, then sure, go for it. Also, the people doing these types of conversions are usually mechanically inclined to begin with, so not really a beginner's DIY option in our opinion. Just remember, you get what you pay for.


We've heard nothing but good things regarding Bostig's support. In our research no other DIY option came close. The Bostig community is full of helpful people too. Check out the Facebook group:

Don't get me wrong, we've heard great reviews for Rocky Mountain Westy, Stephen's Autohaus, etc. We are not slighting them in any way, and if you're in California you will need to go with one of these vendors. See more below.


If you live in California the Bostig conversion is not officially legal due to silly CARB requirements. Ironically, the Zetec operates something like 75% cleaner than the Waterboxer. Apparently this does not matter to CARB. Why not?! Politics and/or bad policy. Rumor has it that Bostig tried to get CA smog approved at one point, but it all fell apart due to no fault of their own.

People claim you can register your Vanagon in a non-smog county using a P.O. Box or a friend/family member, but we have no firsthand experience with this. Pursue this route at your own risk! If you live in the grey area of this map (opens / downloads a PDF) you only need to pass smog once and then you're good to go until if/when you sell it. This is pulled from the CA DMV website:

Vehicles within specified model-years registered in the Change of Ownership Areas are subject to Smog Check only upon change of ownership or initial registration in California. Vehicles registered in this area must receive a TSI (Two Speed Idle) Smog Check.

This sounds great until you realize that the one-time smog check also covers verifying the proper engine is in the vehicle. If it was as simple as a tailpipe sniffer test, you’d be good to go. But it’s not. California has a long list of rules that we're not going to get into. If you want the details this 2018 document (opens / downloads a PDF - scroll way down to Appendix E, roughly page 69) will give you a laundry list of requirements for what’s required; you’ll quickly see why trying to register an engine conversion is nearly impossible. The crux of the issue is that the donor engine (Zetec) must meet the emissions requirements from the donor vehicle (Ford). That is illogical to us. You should only need to match the emission standards of the original motor (Vanagon Waterboxer). To make modern engines fully backwards compatible in an older vehicle, including every little emissions gizmo ever created, is much more difficult…to say the least. In theory, California’s end goal is to have cleaner burning vehicles on the road. The fact that you can legally run the old, dirty Waterboxer engine but not install a new, cleaner running OBD-II Zetec is beyond ironic. On top of that, you could easily argue that engine converted vehicles are so rare that they would have little to no impact on the overall smog condition of that state. But I digress…

Some engine conversions have managed to get what’s called an “Executive Order” or “EO” for short. It’s still unclear to me on how this is achieved.

In theory, if you could convince a BAR referee that your vehicle is legit, anything could pass smog. Think you can do that? The likelihood of that happening without an Executive Order is slim to none unfortunately. With that being said, anything is possible if you know what you’re doing. But again, pursue this route at your own risk!

Ground Clearance

This is an urban legend within the Vanagon community as far as we're concerned. If you actually search for it, you'll find that pretty much anyone complaining about it doesn't even own a Bostig converted van, go figure! Apparently the "Syncro Bo" ( build actually gained a half-inch of clearance vs. his old 2.2 Subaru conversion:

This fact apparently doesn't deter random people from "bashing" the "poor" clearance Bostig has. I hate to say it, but they simply sound ignorant on the topic. Sure, if you only compare the standard oil pan you'll almost certainly see a reduction in clearance. However, if you use Bostig's High Capacity Oil Pan, which many (most?) people opt for, and certainly Syncro owners would, it will have no problem holding its own verses the competition.

As an example, here's the Bostig conversion in action with a 2WD Vanagon. (Imagine what a 4x4 Syncro could do!) As you can see in the video and comments, there are no concerns with power and ground clearance. (The video is shown below, follow this link to view the comments:

A post shared by Tim Hasty (@south_by_syncro) on

Last but not least, here's a video straight from Bostig showing a comparison:


In our opinion, there's not much of a debate when you really dive into the details. If you want to spend quality time in your Vanagon, as opposed to spending time working on or under your Vanagon, on paper Bostig is the clear winner. Once you're up and running it just works.

We have completed our Bostig conversion and are working on getting the content up on the site. Click here to see see Part 1 of the install! We also plan on adding a review once it's all said and done and we have a few thousand miles under our belt. This will hopefully validate everything we have laid out here. We will update this post when the time comes!

5 October 2015

NOTE: This post has been updated from time to time by adding new, applicable examples to the original post. Last update October 2018.