TDI XJ MPG testing. Unbelievable

[@heyyoubuddy6749]

That is incredible, my buddies xj gets about 14 mpg it’s a 4.0ho. Just gotta love the tdi!!!

[@TDISwap]

I'm going to guess it's probably closer to 40 MPG. This number is just too high to believe.

[@dakota121078]

This is very inspirational. I am putting together pieces for my swap. TDI into 5spd 3rd gen 4 Runner.

[@heyyoubuddy6749]

@@TDISwap my wife’s 2015 Passat tdi that was destined and choked off still gets 41 when I drive it. I’ve gotten 47 on a road trip to yellow stone. I’m collecting up parts and trying to find a good donor car. What ever I get will have to be rebuilt. Most cars have a ton of miles on them. Thanks for sharing I really appreciate all ya do for us guys out here.

[@OliverFetter]

Dank!

[@TDISwap]

Thanks buddy.

[@krytios1]

I'm starting a 1.9 swap on my 88 Land Cruiser. Following! I hope to finish this quickly.

[@TDISwap]

Best of luck my dude! Can't wait to hear how well it comes out. Make sure you get whatever turbo you plan to use. I always recommend a GTB-GTD turbo setup as opposed to the older GT turbos.

[@danielwalker985]

what size of tires are you running and what's your gearing? my Tdi xj has auto trans 3.55 gears and 33 inch tires. engine is bone stock no tune bew out of a 2004 Jetta. I'm averaging 23 mpg driving a mix of dirt road, town, and highway so far and have about 8k miles on the swap. The first few times checked my mpg I would only drive 25-50 and my calculations would show anywhere from 35mpg to 75mpg. It didn't seem right so I started filling it till it clicked then would drive till it was almost empty then refill and check and then it started coming out to 23mpg. so far my best is 29mpg driving highway at about 55-60. my worst was 19mpg I had a roof top tent and was driving into the wind at 70+ mph and towing a small trailer with a Harley.

[@TDISwap]

Right now they are P rated 31" tires, standard Michelins. My gearing is 3.54, and this test was done in 3rd gear w/ the TCC coming on @ 45 and higher. My engine is a full hybrid PD150/ALH with Jarod March .280 custom injectors, a GTD1756VK turbo, and a Tekmektronics tune. I also run an electric power steering pump. Not sure if that changes things, or matters, but it's there, lol. The problem with using fuelly, or filling up a tank and going about your business is that you put in so many different factors (traffic, temp, humidity, stop signs, speed changes, elevation changes, tire pressure variations, etc). While this test is not scientific, it makes sense to me to test my vehicles here. It's a straight shot, back and forth. I figured it would long enough for me to burn through a gallon a diesel since I got 34 MPG on my CJ7 with 29" tires and 3.31 gearing (I've since changed to 33" and 4.10 gears), but I was wrong. It's kinda like going on a dyno. We might have the EXACT same car (they were cloned) and our numbers might be different, hence why we're told to not go just off those numbers, but the changes to the tune/motor/mods on the same dyno to see how much better it got. I do plan to put on tires in the next few months as these Michelins are on their way out. Additionally I plan to install some gears (either 4.10 or 4.56), new axles for the rear 8.25 so I can run a truetrac, and maybe a tire carrier bumper as well. I'm sure this will change my data, so I'll be sure to do another and then we can compare. Finally, you're comparing a PD to a VE. VE's, from my experience (and that's reading a ton as I've never owned a PD) is that they get roughly 10% better MPG. Wife had a 2012 CR, and that was sweet! Additionally you have to take into consideration that your stock tune was not made for MPG or power, but more than likely for emissions. This was one of the motivations for moving away from the VE pumps (from what I've read). The tunes that I run are CLEAN. There isn't much soot at all from this setup. With the HE200WG on the CJ there is a little more, but that's also the nature of the WG turbo. If I was to take it up to Tekmektronics, then I'm sure we could get it dialed in a little more. In the end, this isn't a pee-pee measuring test. Rather, this is just me putting out my data, the way that I tested it. I don't fill until it clicks, but rather allow it to foam up. I can visibly see where the foam is as those pumps (for whatever reason) go SO slow with diesel. The only difference I can think of between those two fill ups is the diesel fuel might have been a tad bit hotter on the return, but I don't have a fuel temp gauge like I do on my CJ, and I didn't have the laptop hooked up since the VE pump has a temp sensor inside it. Good to hear that you're enjoying your swap though. In truth, I didn't think I was going to like the XJ as much as I do. I plan to eventually put my Tundra in the garage on a battery tender and driving the XJ as my DD. The CJ will see summer trip duty, and if I go to shows with it.

[@TheHdmotorman]

Last time i checked my tacoma i was getting 35to37mpg with junk mtdi pump and sometimes spirited driving. I'd be willing to bet your atleast 45mpg.

[@TDISwap]

That's really impressive my dude. If it's a Hans/Prothe pump, please be careful. I'm sure you know those are prone to failure and messing up injectors.

[@TheHdmotorman]

Yeah, I'm well aware. We've talked before. Waiting on life schedule to upgrade to e11mm pump jam .280's and gtb2056v with head studs... got all my parts except plumbing and electronic actuator for turbo. I can't say thanks enough for all your help and support of this community.

[@TDISwap]

@@TheHdmotorman no worries my dude! I'm just glad we can all have fun together, lol.