Diesel vs gas for a wheeler

YotaAtieToo

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This has came up in a group chat a few times and the UK guy is all about diesels.

I don't have any real experience wheelin with diesels on a real trail. I always wrote them off as it seemed like the US was pretty limited to 1 ton diesels or a vw tdi. Having owned a tdi jetta, I think they maybe be good Sami engine, but much bigger rig, I don't think its a good choice. "you can tune to 300hp or whatever" ya, fine, I still think it's too small of an engine.

The R2.8 has obviously been out a while and seems to get raving reviews. But that's all from a certain crowd if you know what I mean.

Anyways, boarder line chitchat, just curious what everyone thinks about them on the trail?
 
One of their huge advantages is the better fuel economy. If one of your goals is to be as light as possible, you're better of with a less efficient gas engine and carrying more fuel. Same math is why small airplanes are gas.
 
Do you want to get there fast and loud or do you want to get there slowly and surely with a ton of torque and stink the place up? In my mind thats the deciding factors of gas vs diesel.
 
i think if its an older non-common rail diesel with mechanical injection, depending on where you live and where you wheel at altitude will make for some rich exhaust and your trailmates will make you be tail gunner. In MT i lived at 4000ft but routinely wheeled between 6-9000ft. one of our club members had a samurai powered by a chevette diesel (isuzu). lower elevations were fine but it smoked and stunk up the trail at altitude.

some older diesels had altitude compensators too i think but not all.

I really liked my HZJ73 Landcruiser as an all around do everything rig. slow as hell (non turbo) and ran rich and ****ty at altitude. going to the coast and driving at sea level really woke it up. got good mileage. sounded rad. had to remember to carry anti-gel every time in the winter. also was a glow plug engine so extreme cold made it a BITCH to start.

I would 100% be curious if the body swapped roxor idea would be better at altitude since its is a efi common rail and can adjust itself for altitude.

then there's weight issues with diesel engines generally being waaaay heavier, fuel is more expensive, fuel filters, water separators, etc
my .02
 
One of their huge advantages is the better fuel economy. If one of your goals is to be as light as possible, you're better of with a less efficient gas engine and carrying more fuel. Same math is why small airplanes are gas.

Their are some light diesel engines made these days.
 
Not a fan of them. They put out too much torque at idle, especially in a manual. All the 4bt rigs break the traction too easy, unless it's extremely heavy.
Wheeled with the TDI that Xtreme4x4 built and it was awful compared to all the light gas rigs with the same axles.
 
I think that's the issue in the states, we all have limited experience with some older **** box. :laughing:

Buddy is talking up the om642. 3.0 aluminum V6. Makes 225-265hp and 400-450tq stock 300/500 easy with a tune. Wieghs about the same an aluminum ls according to the internet.

I feel like I'd love in my 4runner, ifs 35s, exploring type rig. But not convinced I'd want it in a true rock crawler.
 
Tldr
I'm just some kind of knuckle head wanting a first gen with a idi.

2lt sux, turbo be damned...
I want it to act like a 3rz.
So far it looks like kubota.
Even the British **** ain't impressive...
 
Tldr
I'm just some kind of knuckle head wanting a first gen with a idi.

2lt sux, turbo be damned...
I want it to act like a 3rz.
So far it looks like kubota.
Even the British **** ain't impressive...

Most kubotas are low power too
 
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I have a few buddies with diesel powered rigs, for overlanding they seem to be fine, but for trail use they seem to sink in mud, don't have the rpm to clean the lugs out and have a hard time climbing ledges. The torque is nice with the diesel and the extra weight up front is nice for climbing steep hills that aren't slick. The only guys I see up here making it work are the moose buggies on 50in+ tractor tires and the only reason they are using diesel has to do with fuel economy as they are out weeks at a time.
 
Not trying to say those aren't valid points. A 12v is ~1200lbs plus intercooler and pipes. That's a fair amount more than even an all iron big block.

fwiw:

The om642 revs to 4500 and wieghs about the same as an aluminum ls.

I'd be very interested to see how an engine like that would work. I've seen videos of pretty built rigs in other countries that look like they absolutely rip with black smoke shooting out. Always curious what they're running for engines.
 
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Diesel was great for a mostly road/mild trail rig. The torque helps with the extra weight of tires and parts. Have a turbo on the smaller side to keep lugging down. Nice being able to cruise highway at a low rpm and let it spool up down with load. Maybe someone can explain it better, but the diesel likes a consistent load.

Gas seemed better for trail rig/crawler.
 
My deciding factor is simple... what will be in the jerry cans on the trail? I'd hate to have to sit for a long time for someone to roll up with a can of diesel.

I personally prefer V8's in my wheelers with plenty of off idle wheel spin up. On my FJ55, I sized the gas tank appropriately(40 gals)
 
No wheeling experience with diesel, but having owned several big diesels there’s no way I’d want one on the trial. 12v, powerstroke, duramax all sound ridiculous to have rock crawling from just a noise standpoint alone. Last years UA had several complaints about it, and seeing some of Ultra4Jones 7.3 bronco wheeling it just sounds annoying, literally.

R2.8, TDI, Jeep Eco, I’d consider those from an efficiency standpoint but then the Jeep Eco gets ruled out from a complexity standpoint.

R2.8 and TDI I’d consider for a light rig.
 
Anything post 07 is gay...full stop. Common rail is quiet and makes power but is overly complicated. Most manufacturers make them ties to a dealership or difficult to repair. Most also have troublesome expensive parts.

The R2.8 is pure Chinesium, has a lot of of quality issues if you dig deep, expensive, and there is no over the counter equivalent in the US so you aren't exactly waking into NAPA for parts. Yeah they get rave reviews by their sponsors.

V8 power, pick your flavor, any Magnum/LS/Coyote will do if it fits your powertrain. More power the better. Torque when you need it, revs when you need it. IMO 20 gears and 90 hp went out with the 90s.
 
My deciding factor is simple... what will be in the jerry cans on the trail? I'd hate to have to sit for a long time for someone to roll up with a can of diesel.

I personally prefer V8's in my wheelers with plenty of off idle wheel spin up. On my FJ55, I sized the gas tank appropriately(40 gals)

I know anything can happen, but I can't remember the last time I've had to take gas on the trail. Heck, I haven't even needed my 2g back up can I carry for years.

Wtf are you doing that takes 40 gallons? Even big V8s usually don't burn much doing rubicon.

Anything post 07 is gay...full stop. Common rail is quiet and makes power but is overly complicated. Most manufacturers make them ties to a dealership or difficult to repair. Most also have troublesome expensive parts.

The R2.8 is pure Chinesium, has a lot of of quality issues if you dig deep, expensive, and there is no over the counter equivalent in the US so you aren't exactly waking into NAPA for parts. Yeah they get rave reviews by their sponsors.

Somehow that never crossed my mind about parts availability.

And ya, can not find any reviews besides influencers and people who payed $25k for everything at a shop.

Fred Williams has one and seems mostly happy with it. Well, the jeep hasn't sold, but he does seem to take the JL more lately. Maybe Beat95yj has some inside info on it?

I did notice most of the UA rigs that were built during the R2.8 sponsored era are not seen as much anymore.

V8 power, pick your flavor, any Magnum/LS/Coyote will do if it fits your powertrain. More power the better. Torque when you need it, revs when you need it. IMO 20 gears and 90 hp went out with the 90s.

My path of fun and wierd engine swaps always lead back to ls, cost, packaging, ect.
 
I know anything can happen, but I can't remember the last time I've had to take gas on the trail. Heck, I haven't even needed my 2g back up can I carry for years.
I've come close a time or two. My old FJ40 didn't make it through Con with small tank(15 gal) and a 5.0L TBI and I needed to fill from my 5 gallon jerry. That was a fill in Placerville.

But I also tend to play a bit too much "concern" building :shaking: If I were building a "lighter" rig, I'd run a smaller tank(10-12)
Wtf are you doing that takes 40 gallons? Even big V8s usually don't burn much doing rubicon.
Not a thing... it just happened to be the biggest custom size that would fit in the rear and not hang below the frame rails:

jstank12.JPG

jstank11.JPG


I don't have the measurements in front of me(15 year old tank) but I want to say 32"x32"x10". Since the above picture, it got better mounts and a skid plate. I love the tank because it would find the credit card limit at all gas stations when I was doing regular fills on it($70 usually)

I hear you on weird engines... I've bench built too many and have a BB Cady swap in the fleet:shaking:
 
Diesel for long adventure trips for mileage, gas v8 for trail riding fun.

We have lot of older diesel offroaders here in Finland and usually they are not that great.
Some newer mercedes and bmw tuned "superdiesels" are better, but the short rpm range and need to be on boost makes it more difficult if sudden need for tire speed comes up. It can be done for sure, but I like the gas V8 approach.
 
If Europeans could get cheap gas engines and cheap gas fuel the way that we can, they'd use a ****load less diesels in things.

But they've got a ****load of diesels and everything is expensive anyways, so they might as well use diesel and get a little better efficiency.

For the price of a brand new r2.8, I can have any number of very nice gas engines that will outperform it in every way except fuel economy. Same for any other small diesel. Most of the turbo diesels aren't any smaller or more power per volume than gasoline.

For a novelty , sure. The only cheap diesels are old. Old ones are loud for no reason and terrible for power
 
Can't say I have wheeled around diesels. But it seems to me that hp is hp. And you gear to have the torque and wheel speed you want. And it seems to me, at least in the U.S., that gas wins in power, weight, parts / upgrade options, and throttle response.
 
East Coast we need more RPMs to clean tires. Crawling they seem like they have too much torque. There's times I can choke down my motor to barely running and just pat the gas to crawl stuff.
 
Do you want to get there fast and loud or do you want to get there slowly and surely with a ton of torque and stink the place up? In my mind thats the deciding factors of gas vs diesel.
You know you can put a muffler on your engine, right? :laughing:
 
East Coast we need more RPMs to clean tires. Crawling they seem like they have too much torque. There's times I can choke down my motor to barely running and just pat the gas to crawl stuff.
That's where the newer small diesels are decent, they don't mind going to 5k rpm
 
The argument that diesels can't clean the tires never made sense to me, that's what the gear is for......now trying to reverse out, I get that can be gear bound
 
I have wheeled a couple diesels. Not a fan for rock crawling or challenging trails.

There are advantages of course like low speed torque, They can be smooth and quiet and efficient, but when you reach an obstacle that stops you, you start stepping on the peddle to build torque to climb it. Once that torque is built and you start to move, it is like oh crap now there is too much torque.
It is really hard to be gentle when wheeling a diesel. I think of it maybe like a rubber band. turbo is spooled, torque is up, rpms are up. It has to go somewhere.

you also have a really hard time "bumping" over objects.

But these were also big heavy trucks. Might a completely different experience in a light little buggy.
 
Can't say I have wheeled around diesels. But it seems to me that hp is hp. And you gear to have the torque and wheel speed you want. And it seems to me, at least in the U.S., that gas wins in power, weight, parts / upgrade options, and throttle response.
To me, it seems that diesels don't spin up RPMs as quick nor have as much RPM available when compared to gas. Gas seems to have at least 2k RPM at the top.

I've got a TDI in my fleet and it does okay. I will grant you it is very under powered but it takes a while to get RPMs and the usable RPM is 600-3400 or so. In comparison, both my gas Toyotas(3.4L and 4.7L) have 600-6000rpm on hand.
 
I'll readily admit that the TDI swap I'm planning into my yota was somewhat influenced by Nate at Dirt Lifestyle. He seems to really swear by the idea overall and I drank the koolaid a bit. I've since become unsure how well it will work out, but I'm also not going to be too bent out of shape and will try something else if this doesn't pan out.

For my specific application, an ALH swap into my truck presents a few points that made it seem worthwhile.
  • I currently run propane, so going back to a fuel I can get from the pump in large quantities is attractive
  • The ALH weighs effectively the same as the 22RE
  • Planning on tuning, so peak numbers will land at around double the hp and triple the tq of the 22RE
  • Large efficiency increase
  • Adapters readily available
  • TDIs are harder to get parts for than 22REs, but still common enough to get whatever might be needed in a reasonable time frame
Basically, since I got the running driving TDI parts car for $600, there isn't an engine that can multiply power output and increase fuel mileage with no weight penalty for like $6500 all in.
 
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