The Toyota Landcruiser Owners Club

[paulh]

Diesel vs. Petrol?  It's a great debate, but only to be entered in with a sense of humour, I feel.

Diesels are probably cheaper to run, but petrols are cheaper to buy.  So from a straight economy perspective, if you plan to keep it for a few years the diesel is the best bet.

However, even the 200+ HP turbo-diesel in the 100 won't shift it off the line like an FZ or UZ engine would, so you have to consider your driving habits.  If you like to occasionally drive your 'Cruiser like a sports car, then you need the petrol.  Granted, you can spend money on the diesel to give it some more pickup (intercoolers, pump tuning, propane injection, etc) but then you have to think that you might as well have bought a petrol in the first place.  Spending the same amount of money on a petrol will get you an LPG conversion that gives you the economy of a diesel, but you still have the petrol's perfomance.

I'm a little biased, in that I went to work in the Middle East in the early 80s, and was given the keys to a brand new FJ40.  Those who haven't driven something with a 2F engine in big dunes, and say that diesels have more torque, should try running their motors down to about 100 rpm and see if they can still get up the hill.  I tried HZ motors in Australia, and 3Bs in Turkey, but neither had that 'keep running at any speed' feeling that the 2/3Fs had.

I can't really comment on the FZ engine though.  Mine has the automatic gearbox, which tends to mask the real characteristics of the engine.  However, the Bedu in Oman and the UAE still prefer FZJ78s to HZJ78s, although you can get much farther on two tanks of diesel than two of petrol.  The price of fuel isn't really an issue out there, and you can always strap a 40 gallon drum into the back of the pickup if range is going to be a problem.

So, in short, don't be dissuaded by folk who say "I personally wouldn't entertain a petrol.  Diesel is the only real option for the big stuff." I once entertained a couple of guys from the Australian BHP oil company, who'd come to Oman to position survey points for offshore drilling.  We went off in FJ75 pickups, and all I heard from my passenger (apart from minor complaints that the A/C wasn't working, which was true, but who needs aircon when it's 40 degrees in the shade? Just open the fjcking windows...) was 'Why don't you run diesels? It'd be much cheaper, you'd have more range, blah, blah, blah.  Anyway, part of our recce mission was to drive down the beach past the Sultan's palace, but we didn't know that he was in residence at the time.  So when the machine-gun armed guard started to wave his M16 (or similar) in our direction I decided that the best move was a U-turn.  Now, a U-turn in soft beach sand is probably not the best thing to ask of any vehicle, but I kept my foot to the floor and we eventually pulled out of it.  My passenger's comment? "I can see why you guys run petrols!"

So don't be swayed by blanket comments.  The diesels are far from wanting, you just have to see what Ian and Toby and Jon do with theirs, but don't let that you put you off buying a petrol.

Anyway, I wish I'd been as keen as writing essays when I was at school - I might have been a banker by now...

Cheers

Paul

[Google]

[Brett]

[Wandering Willy]

If you look at the torque curves of various types of engine (why do anything else?). you would see that petrol engines peak at 3,000-5,000 rpm depending on its tuning. A nominally similar diesel engine peaks between 1,500-2,500rpm. If you add a turbocharger to either type, the more power you get an engine which delivers more power and torque, but at a higher engine speed.

Looking at Land Cruisers and similar vehicles, those with smaller engines (e.g. 2.5 litre Disco's) have more of their power courtesy of the turbo, hence the higher the rpm when you get peak torque and power. This is an approximation to the truth, however, it is a good rule of thumb when considering a replacement vehicle.

This higher state of tuning looks good on paper but is not so nice in reality. This is apparent when you look at other parts of these cars. LCs have changed; older cars had a 3 speed automatic, then it was 4, then 5 and for the 200 it's a 6 speed box. The same is true of other manufacturer's cars. A lot of VWs have a 6 speed manual box. This is because you only get peak output over a narrow band of engine speeds. It either delivers little on one side of the peak power speed or runs out of breath on the other side.

Given that recent/current cars are typically heavier and carry a lot more equipment than cars 20 years ago, it is difficult to suggest a direct comparison. If you look at what are now older cars, they had a normally aspirated engine (no turbo) which was big enough to produce adequate power given the weight of the vehicle. The new 200 series needs a 6 speed automatic gearbox. I worry about that car.

If you want a vehicle (car?) with high torque at low engine speed, fit a steam engine. The old steam locomotives could spin their wheels when stationery and would do so almost every time they started - it was impressive but damaging (to track and wheels). These engines weren't very efficient compared to a modern diesel so this might have its downside. However, I think you could make a small high pressure boiler and use a steam turbine to produce huge power from stationery. I have seen a single stage steam turbine (in its housing) which was the diameter of a dinner plate and about 5cm thick which produced 1000hp.

Electric motors can also be designed to produce high torque at low speed if that is what you want. Such a motor isn't very efficient and can get very hot (it's like a slipping clutch). but for a 'Super 4X4' it might be a good proposition. Hybrid cars don't have this sort of low speed/high torque electric motor just one with a wide power band to operate efficiently at town speeds.

So what are we left with? How about a robust diesel engine with adequate maximum power (fit a small turbocharger, perhaps?) but with 80% of maximum torque from about 1000rpm. Peak power wouldn't be enormous because such an engine tends to have a low maximum rpm. You could also fit an extra low bottom gear. No, I have a better solution; put a speed changing gearbox on the output shaft to reduce engine output speed and increase the delivered torque. Now wouldn't that be a clever arrangement!

(tongue now removed from cheek)

As I see it, the current manual high/low transfer box could/should be replaced with an automatic unit. Then it would automatically slide into low gear when full power was demanded at low wheel speed. Something like the old type of overdrive unit could do this if it was suitably geared and strengthened. Obviously, you could isolate low drive for normal driving to avoid all 4 wheels spinning when pulling away from the traffic lights. It might be nice to have this automatic transfer box when towing a heavy trailer and needing to get out of a junction or enter a roundabout.

Willy

[Audzatstods]

Thank you Willy and Paul,

I have swithered about going diesel, but we have a diesel 4x4 already which im more than happy with. I just fancy having a nice quiet torquey Landcruiser that i can sink the boot on and overtake as in the north of scotland we dont have many overtaking opportunities, so instant power is what i need and my other 4x4 gives me that, so anything slower would be annoying if you know what i mean.

Ive never driven the petrol or diesel version, so what ive learnt about Landcruisers is from what ive read on these forums, the diesel is obviously more popular, but petrol seems to be the one that you race off from the traffic lights against the boy racer!!!

Anyway as we have had a fair fall of snow this week already (its all gone now) and the main reason for us getting another 4x4 is to put our sporty car in the shed, so i need to get my finger oot and decide what to do.

Thanks again for the comments, i am taking it all in!!!!

Auds

[wildsmith]

The UZJ economy is hopeless if the sound of a v8 puts a smile on your face, they've tuned the exhaust just right  

I test drove some comparable diesel and petrol 100's before getting our petrol one because for cruising the petrol was / is a much nicer place to be.
_________________
Jon m0zxj

01 UZJ100 lifted (AHC & 40mm BL), ARB locked f&r, cryo'd 4.88's, TJM front bumper, 12k goldfish, sliders, rack, snorkel, 35's, storage, aux power etc.
93 HDJ80 sold
94 HDJ80 RIP

[Audzatstods]

Right my latest quandry, is whether i should go petrol or LPG!!

Basically im looking at two cars, same age, same sort of mileage, same MOT and tax etc, but the lpg one has had 5 owners was converted 18months ago, is 300mls away, doesnt have a service history and costs 500 more than the petrol one which has had 2 owners and is only 100miles away with a partial service history.

We had an lpg shogun before which kept going out of tune which was probably something to do with the kit, but it took ages to fill the tank and im just wondering whether the saving is worth all the hassle??

Comments greatly received please.

Thanks

Auds

[wildsmith]

For me there's too much doubt about the longevity of engines on LPG conversions, seems to be not uncommon for people to have valve / head issues eventually. If you go for LPG and then end up needing a top end rebuild it will wipe out any saving you made on the fuel and then some! If it came from Toyota as LPG I'd risk it but I'd take a lot of convincing to buy a car with a kit someone else had fitted, who knows what trouble is saved up for the next owner ...
_________________
Jon m0zxj

01 UZJ100 lifted (AHC & 40mm BL), ARB locked f&r, cryo'd 4.88's, TJM front bumper, 12k goldfish, sliders, rack, snorkel, 35's, storage, aux power etc.
93 HDJ80 sold
94 HDJ80 RIP

[paulh]

Whilst I can appreciate Jon's comments regarding top-end rebuilds, the Aussie forums (fora?) don't seem to be full of the old LPG=Broke FUD.
OTOH, I've thought long and hard about converting mine, and have just about reached the conclusion that it's not worth the effort.  The FZ motor is a star in the galaxy of sound engines, so why should I compromise it?  Nobody said owning a 'Cruiser would be cheap, so at 17 mpg I'm not that far off a diesel. (given the 10% differential in the fuel cost)

Paul

[Audzatstods]

Thanks for the comments.

A top end rebuild is obviously not something i want to have to do because of LPG, but has anyone had to do it on these forums, ive had a quick look to see if anybody has written in and would be very interested to hear from anyone whos had problems with an LPG car.

Like i said i had a Shogun that had to be tweaked at least every six weeks or would stall constantly, it was a cheap kit that was fitted by a guy who was a lecturer of engineering, but i got rid of the car because it was too much hassle, think im talking myself out of LPG here!!!

Is 17mpg the typical consumption of the petrol LC ? As i do intend running it daily and a 50 mile commute sounds like its going to be a tad expensive to run, hence the thoughts on LPG?

Well if i dont make my mind up shortly i shall lose them both.

[gilghana]

Not related to the questions really, but I do have to point out that I drove a 200 series (fairly basic model) last week with a manual gearbox.  Doesn't have to be a 6 speed auto.  The car had PLENTY of useful power throughout the rev range.  The power train doesn't concern me as much as all the electronic EVERYTHING that goes along with it.  Stuff up a river crossing as I did in a 105 series and I reckon it may as well be a write off.
G

[Audzatstods]

An update for you:-

We hope to take delivery of a Landcruiser later this week, you will think im mad as i havent seen or test driven it, but taken the word of the guy whos selling it that its a genuine car!!

Its coming up from middle england on a transporter, so i shall let you know how it goes.

[joinerman]

Fleabay purchase?,  Hope it's as good as described & keep us informed.

[Audzatstods]

Well ive just taken delivery of the Landcruiser, as it was dark i didnt get a good look round it, but for what i could see it looks fine.  Bear in mind that ive never driven a LC before, so my first impression of the driving experience was that it wandered a bit on the road, but otherwise was fine.

Tomorrow we shall have a good look round it and take it for a good run to get into the way of it.

I shall issue you with a further update the morn.

[Wandering Willy]

Just a hint. The tyre pressures on these cars can be adjusted to suit what you are doing. If they are a little soft - it's great off-road over mud etc. but if you want to drive on a motorway they need to be a little bit harder.

Because the tyres are not low profile (they are high profile I suppose) the flexibility of the sidewalls impacts the car's handling a lot. Raising the tyre pressure reduces this flexibility and the car is more stable at speed. Check the maximum allowed pressure on the side of the tyre - different tyres have different maximums.

Juggling the tyre pressures like this is more of an art than a precise science but try a bit up and a bit down and see how it goes but be careful while you are doing it.

Willy

[Audzatstods]

Cheers Willy, you are an absolute wealth of information which is greatly appreciated.

Can you tell me what else i should look for when we check it over tomorrow.

Cheers

Auds