Diesel powered to US

[Emil]

So I've done some work on petrol v diesel. Long post for anyone interested in a running cost comparison.

We have a choice of engine in Australia. I really wanted to pick petrol because I think diesel has a limited long term future, but I picked diesel again because that is the better option for me because I tow a camper and I travel long distances when I'm on road trips.

We're a metric country so @ryket's 18 US MPG converts to 17.07 litres/100km.
My long term diesel average combined economy is 11.5 litres/100km (20.55 US MPG).
My highway average is 10.8 litres/100km (21.78 US MPG).

On an MPG basis my diesel is not significantly better than ryket's petrol (gas). Economy is just one part of the story. Running cost and range per tank are others.

Unusually, there is no difference in purchase price for petrol or diesel and the relative servicing costs don't appear to be a significant either so the diesel v petrol decision largely comes down to running cost and pattern of use.
Some buyers will naturally shy away from diesel because of the Euro 6 DPF and DEF (AdBlue) requirements and cost. In my calcs below I have added the cost of the AdBlue to the diesel running cost so it's not overlooked.

I have updated my calc sheet for today's fuel prices in my area and used 18 US MPG (17.07 lts/100km) as a benchmark to see how that compares to diesel.
Diesel is still ahead.

Don't worry about this being metric. Just observe that diesel is costing me less to run and is getting me further down the road per tank. For my usage, diesel is the better option. If I increase the distance travelled per year (15,000km) the running cost tips even more in favour of diesel.

And that's been the general (and simplified) consensus on the petrol v diesel coin toss:
- Low annual usage and weights, or hate the necessary diesel emissions tech - pick petrol.
- High usage, need longer range or higher torque for towing then pick diesel.

These numbers are non-towing. When towing I get about 16.8 litres/100 km. Anecdotally I believe the petrol runs around 22-25 litres/100km towing (10.7 to 9.4 US MPG).

View attachment 7887502

I first built this calc sheet in 2022 to help me choose diesel over petrol. It's tracking very close to my actual 12 month stats (below) for 16,443km travelled.

View attachment 7887504

Well said. For sake of completeness, there might be other groups of drivers who can experience issues with the diesel: When driving only short distances, the diesel particulate filter has to be run free once or twice a month, which may be annoying (I have observed this with my diesel GC, dealer confirmed it, that is why I ultimately opted for the petrol). Regeneration of the diesel particulate filter generates noise, but above all high heat, which should be avoided while standing in high dry grass (read this in forums). Extreme overlanders or drivers in some countries might find it difficult to source AdBlue when needed, and the B58 engine might tolerate bad petrol better than the B57 bad diesel (according to forums). More comfort-oriented drivers may prefer the petrol over the diesel (I find it less noisy and better suited on-road); at the same time more off-road oriented drivers told me they do not miss the additional diesel torque (unless towing heavy loads). In essence, decision very much depends on the individual use case (for long-distance towing, I would have bought the diesel). It's a pity that in some markets buyers can't choose, especially as the diesel engine is usually more expensive.

 

[Clark Kent]

Well said. For sake of completeness, there might be other groups of drivers who can experience issues with the diesel: When driving only short distances, the diesel particulate filter has to be run free once or twice a month, which may be annoying (I have observed this with my diesel GC, dealer confirmed it, that is why I ultimately opted for the petrol). Regeneration of the diesel particulate filter generates noise, but above all high heat, which should be avoided while standing in high dry grass (read this in forums). Extreme overlanders or drivers in some countries might find it difficult to source AdBlue when needed, and the B58 engine might tolerate bad petrol better than the B57 bad diesel (according to forums). More comfort-oriented drivers may prefer the petrol over the diesel (I find it less noisy and better suited on-road); at the same time more off-road oriented drivers told me they do not miss the additional diesel torque (unless towing heavy loads). In essence, decision very much depends on the individual use case (for long-distance towing, I would have bought the diesel). It's a pity that in some markets buyers can't choose, especially as the diesel engine is usually more expensive.

All good points @Emil thank you.

It's an eyes wide open decision, but only necessary where there is a market choice.
I think @Logsplitter and @Matt P are probably two of our more intrepid travellers that have journeyed to less developed areas and my recollection is they both chose petrol engines for the reasons you say. @globalgregors is another wandering nomad but I cannot recall if he has diesel or petrol.

I was really only commenting around the running cost factor, following the previous post. My summary was simplified along that line.

Carriage of extra fuel is a consideration. Given a choice most would prefer to carry diesel over petrol based on flammability. Of course there is now options for auxiliary diesel tanks with a petrol aux tank reportedly on the way via LRA.

Winter diesel can be tricky.

The list goes on for each fuel type.

It's not a simple decision, but it is an individual decision.

 

[Zimm]

The way the pricing structure and fuel convenience is in the us, unless you frequently load the f350 up, diesel is a waste.

 

[Shopkeep]

Do diesel engines last longer than petrol/gas? Some of the arguments supporting this theory suggest the components on diesel engines are more robust than an equivalent petrol, this theory is reflected in the version of ZF gearbox chosen for the Grenadier diesel?

 

[Emil]

Do diesel engines last longer than petrol/gas? Some of the arguments supporting this theory suggest the components on diesel engines are more robust than an equivalent petrol, this theory is reflected in the version of ZF gearbox chosen for the Grenadier diesel?

Oh, and the diesel engine is more heavy resulting in lower payload…

 

[landmannnn]

Do diesel engines last longer than petrol/gas? Some of the arguments supporting this theory suggest the components on diesel engines are more robust than an equivalent petrol, this theory is reflected in the version of ZF gearbox chosen for the Grenadier diesel?

Historically yes. Diesel engines used to have maximum power curves that meant anything above 3,500 rpm was pointless, petrol/gas engines revved to 6,500 rpm plus so tended to wear more.

Nowadays I suspect that provided servicing is kept up to date that there isn't much in it.

 

[globalgregors]

All good points @Emil thank you.

It's an eyes wide open decision, but only necessary where there is a market choice.
I think @Logsplitter and @Matt P are probably two of our more intrepid travellers that have journeyed to less developed areas and my recollection is they both chose petrol engines for the reasons you say. @globalgregors is another wandering nomad but I cannot recall if he has diesel or petrol.

I was really only commenting around the running cost factor, following the previous post. My summary was simplified along that line.

Carriage of extra fuel is a consideration. Given a choice most would prefer to carry diesel over petrol based on flammability. Of course there is now options for auxiliary diesel tanks with a petrol aux tank reportedly on the way via LRA.

Winter diesel can be tricky.

The list goes on for each fuel type.

It's not a simple decision, but it is an individual decision.

Diesel all the way for us.

Closest thing to a problem sourcing Ad Blue so far was in Villahermosa, MEX where only one of the six AutoZones around town carried stock (next day delivery for all the others). I habitually check and it’s almost always found as shelf stock in auto stores wherever if not actually available at gas stations or the pump.

Wasn’t sure about Belize/Guatemala so I popped a spare refill in the back before crossing the border which will see us through to Colombia.

Much prefer carrying & handling diesel in remote areas, and prefer the torque characteristics/lower revs of this engine in high ambient temperature slippery conditions such as desert sand or tropical mud.

Offroad use preference should depend on whether one is rock crawling (vehicle usually lighter) or in expedition use (heavier), latter obviously favours the diesel.

Never had any real issues with winter diesel. It’s has to be very cold before it’s an issue and you can use anti-geling additives as a stop-gap. Normally wherever one is that’s properly cold (Russia, Canada) I’d say a block heater is more of a concern.

Major argument for diesel for remote overlanding - to really obscure spots - is availability. With a bit of fast talk you can source a top-up off any passing truck. In somewhere like Iran, Siberia or Central Asia this can be WAY easier than limping to a gas station and will usually play out for a few bucks and a soda, cup of tea or a chocolate bar etc.