Thread: Petrol v diesel economy

Tried to find a new petrol ute lately? Good luck. LPG, even after conversion cost is looking really attractive.

In theory you can run a diesel off cooking oil, people were loading up their shit boxes in the car park when cooking oil was cheap so the supermarkets clamped down and raised the price to boot... cunts!

Originally Posted by caberslash

In theory you can run a diesel off cooking oil, people were loading up their shit boxes in the car park when cooking oil was cheap so the supermarkets clamped down and raised the price to boot... cunts!

I have a fried who runs his older Nissan Navara on a blend of 20% diesel and 80% auto transmission fluid. He has an agreement with an auto box repair shop to take all their used oil. He gravity filters it first from one 200L drum to another through a filter bank, and then centrifuges it so that it is clean for the engine. A bit of work involved but it makes cheap fuel.

My brother was working for a lubrication company a few years ago, and they had an 'incident' where 2,000L of lubrication oil that was being batch blended for the coal mine at Huntly, was incorrectly blended with additives. Oil was toast. $10k worth of oil !! I managed to get if for nothing, including two brand new IBC's. Mate was a very happy chappy as it was a light grade oil and suitable for his Nissan.

Well just ordered the new ranger with the v6 td will be interesting if it used more the my currently colorado, old man looking at getting the new nissan suv with a v8 hopefully he dose then we will get a good comparison.

One of the main considerations for petrol vs diesel is how much the load factor changes on the vehicle. Petrol can be very economical especially with the modern systems that shut off at the lights etc etc, but as the load factor goes up petrol consumption cost increases in a frightening manner. Towing is one of the ways that you can seriously increase the load factor on a vehicle, especially when towing things that have a LOT of wind resistance (boats, box trailers). As soon as you factor in towing and a wide range of load factors, diesel seriously wins on consumption and that's due in no small part to the fact that petrol fuel tax is paid per litre of fuel whereas diesel is per KM meaning it doesn't get much more expensive if your diesel consumption goes up a litre or two per KM.

Diesel servicing is in some cases more expensive - but surprisingly enough some of the lightwieght petrols are by no means cheap come service time (as an aside, some EV's are quite a bit more expensive on service costs than people think - one owned by a neighbour is about 20% worse on tyre useage than the equivalent petrol model for example). People put a lot of concern into common rail diesel engines with fuel pump and injector costs, but some petrol engine designs are just as bad for repair costs. Mate just had to replace 6 individual coil packs and plugs on his wife's trundler, plugs at $55 each and coils at $325 a piece. And then it was a couple of hours of ripping bits off the engine to get to the bits needing replacement, replace a gasket set and some consumables and two hours to rebuild the thing. Total cost around $3500 just to replace spark plugs and coils...

A side factor, some petrol engines are highly allergic to water (a splash into the engine compartment can stop them cold) but some diesel 4wd's are now no better in this regard with the placement of critical sensors and electronics.

Ever see a petrol do 800,000km+. If you are in for the long haul with a vehicle and don't change them like your undies then hard to go past a diesel. I owned my last one for 8 1/8 years and sold it for the same price I bought it for.

Well, perhaps not a million.

Are you confident the European 2.0L TO 3.0l turbo charged diesels with a million gears are going to get to 800Thou K or even half that.
I'm not.

Originally Posted by jakewire

Are you confident the European 2.0L TO 3.0l turbo charged diesels with a million gears are going to get to 800Thou K or even half that.
I'm not.

The ZF 6 and 8 speed autos have been around since 2000 and many are still going with minimal maintenance.
The newest of diesel engines with emissions crap up the wazoo im less confident in.

No. My "new" vehicle was made last century

Don't own a vehicle (car/truck/tractor/dozer) that is younger then 25 years, so finicky electronics are not a worry for me.

Yeah, can't see me selling any of the Patrols now. Happy with their consumption at 10L/100km. A big plus is that they are almost entirely maintainable by joe average home handyman.

Diesel has inherently 15% more energy per litre than petrol.

Didn't know that modern petrols had become so expensive to maintain either.

Originally Posted by XR500

Don't own a vehicle (car/truck/tractor/dozer) that is younger then 25 years, so finicky electronics are not a worry for me.

Yeah, can't see me selling any of the Patrols now. Happy with their consumption at 10L/100km. A big plus is that they are almost entirely maintainable by joe average home handyman.

Diesel has inherently 15% more energy per litre than petrol.

Didn't know that modern petrols had become so expensive to maintain either.

A lot is to be said for the TB/TD 42 motors, old school reliability,

Yeah - it's bloody eye opening when you get the mechanic mate to do the plugs on the mother's little '07 Tiida. Ahhh, bro - that pile of parts includes an intake manifold. Yep, gotta get that off to get to the plugs...

Now - don't get me wrong, the Tiida plugs are cheap by comparison to some of the modern petrols at $45 a piece and only four of them - but even that is three hours of labour just to change 4 spark plugs (including a couple of seized fasteners and other fartarounds). It's a bit of a joke really, Tiida spark plugs are dearer than some diesel engine glow plugs.

The older diesels like the patrols are good in some respects, including not being particularly fussy about fuel (as long as it's compression ignition compatible it's good to go). Biggest issue with them are they are getting hard for some parts, or you are forced to use some aftermarket bit that doesn't really meet the grade for lifespan. I went through three sets of mounts in one of my Safari's, first set were the original factory and lasted 16 years, second set lasted just over the warranty period and the third set were 10 months so I got a refund on them under warranty (rubber parts were separating off the steel sections). I ended up building a set of solid steel and red urethane mounts - they were still going last time I checked after 11 years. Probably need to get a bloody cert if you did that today...

Originally Posted by No.3

Yeah - it's bloody eye opening when you get the mechanic mate to do the plugs on the mother's little '07 Tiida. Ahhh, bro - that pile of parts includes an intake manifold. Yep, gotta get that off to get to the plugs...

Now - don't get me wrong, the Tiida plugs are cheap by comparison to some of the modern petrols at $45 a piece and only four of them - but even that is three hours of labour just to change 4 spark plugs (including a couple of seized fasteners and other fartarounds). It's a bit of a joke really, Tiida spark plugs are dearer than some diesel engine glow plugs.

The older diesels like the patrols are good in some respects, including not being particularly fussy about fuel (as long as it's compression ignition compatible it's good to go). Biggest issue with them are they are getting hard for some parts, or you are forced to use some aftermarket bit that doesn't really meet the grade for lifespan. I went through three sets of mounts in one of my Safari's, first set were the original factory and lasted 16 years, second set lasted just over the warranty period and the third set were 10 months so I got a refund on them under warranty (rubber parts were separating off the steel sections). I ended up building a set of solid steel and red urethane mounts - they were still going last time I checked after 11 years. Probably need to get a bloody cert if you did that today...

Hope you replace with platinum, nothing like snapping a stud off in an alloy head!

Originally Posted by Maca49

Hope you replace with platinum, nothing like snapping a stud off in an alloy head!

I think that Platinum Iridium Newfangled Unobtanium were the only choice we had if I recall correctly. Everything cheaper were out of stock, and by cheaper I mean only a couple of bucks...