Gas and petrol vs diesel

[Tigger77777]

For those who have experienced (gas and petrol) and diesel engines, what are the pros and cons for these types, obviously gas is cheaper but do you get similar power that the diesel provides? And what is the range using gas?
Cheers

[Agronaught]

Unless you go the turbo td42 the petrols will usually have the power edge over the diesels. Of course there are always exceptions and I'm sure they will be pointed out here ;)

Depending on the petrol, it can be a *lot* more power... At the cost of a lot more fuel.

However there is a lot more to 4wd than power. I wish my tb48 has the compression of the diesels for downhills and I'll have to look at reduction gears too get what I want out of my car.

If you do the km LPG can be good. If you don't it's is (IMHO) a false economy. When you take into account the coast of the LPG install and additional service costs it takes a lot of km to make LPG worthwhile. Not to mention it can cause early failure in the engine if it's not maintained correctly.

LPG tanks are also smaller, and you burn more LPG than petrol as it doesn't have the same amount of energy per litre.

A 115L tank only takes 90L of LPG, which is only good for 300km in the city which sucks. I get 370km to 90l of LPG on the highway which isn't great.

If you get LPG you will want a larger sub tank (70L) to improve the range and cater for those situations where lpg isn't available.

It's a mixed bag and depends on what you want to do with the car. Personally im looking to ditch the LPG and put a fuel tank back in there.

[Bigcol]

as Agronaught said, depends on what you want to do........
years ago, Gas was 1/3 the price per liter than Petrol
then petrol went up, and so did gas, now its a no-brainer - its not worth spending the coin to get it fitted to your car.......

if your wanting power - petrol any day every day
if your wanting to tow - diesel - more economical power (more Kms per liter than petrol when towing)
if your wanting cheap weekly fill ups - gas (if its already fitted)

my previous GQ was petrol / gas
with the way the timing is 19.5*BTDC - (Turned for Performance on Gas Btw)
on petrol I had 96Kw of power...............
on Gas I had 93Kw...........
only difference was take offs at lights
BUT
as I tour with a Van.................. when towing said van.......
120L Gas tank = 250kms + 50L petrol tank = 250kms
not a large range for distance but when you hit a hill in gas - you lost speed faster than you would believe

I updated (?) to a GU TD42 (with Gas injection) - was crap with the Gas - just blew a snot load of black smoke....
put a turbo and intercooler on it - yeah team, now its got some poke.............

just have a good think about what you want to do, and whats 80% of your driving............ then go for the one that suites that
I do long distant travelling towing a 2t van - diesel was the way for me to go
around town, I like to steal SWMBO's petrol V8 - easier to drive, zippier around town etc........

[the evil twin]

In a current generation vehicle with all the dodads that mean you can't drive it even if you want to
Range - Diesel
Towing - Petrol
Grunt - Petrol
4WD - doesn't matter, the electronics mean the engine isn't connected to the wheels these days
Does anyone really bother anymore with LPG due to VVT etc etc petty is quite frugal and LPG is almost as dear as Petrol over here and you can't get it out bush

In old school vehicles with no dodads where the Driver actually drives the thing
Range - Diesel
Towing - Diesel
Grunt - debatable
4WD - Diesel
If you can't afford a Diesel - Petrol
Shoping Trolley - LPG

[Patrol'n]

My experience with gas is it was worth the get in price back when gas was 32 cents a litre, once it got up closer to petrol, not really worth it. I like petrol powered myself, so spent ages to find a petrol patrol with no gas installed, (and mines an old school one) :-)

That said, if I had found a GQ diesel in good nick when I was looking, I would have snapped it up!

[Agronaught]

I'm ditching LPG.

now to find an OE fuel tank etc ;)

[threedogs]

I;ve had a dual fuel 4x4 and travelled over 400k in it.
Mind you gas was 18c a litre and worth putting in at that stage
I was getting 400k range, being a big petrol brick [troopy]
on petrol I'd get 450 from 90ltr.
Would I buy a dual fuel 4x4 today no way, in town gas is 70 cents and way higher when you get 100k out
Gas runs hot you either tune for one or the other, carbies dry out, valves recess into the heads.
After Leigh Creek thats your last gas if heading Birdsville way, then youre paying $2 plus for ULP

for Touring you cant beat a diesel if you run out, a tractor or earth working machine can be
milked for diesel. Down size is service costs are higher on a diesel.
What would I buy if money was no option,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,A DIESEL TD intercooled

[Tigger77777]

Thanks all, from what I have read and based on my situation, I will go for a diesel, for the simple fact LPG only gets about 300km per fill, which is a pain to keep filling up regularly. Also I will be towing though it will be light. Well, if no diesels are available at the time of purchasing, a new rig with all the extras and LPG won't be so bad. Cheers

[Jonesy_sa]

I have a duel fuel GQ and would prefer a TD42 diesel even if its a slug. A replacement fuel LPG tank is around $1000 if mine fails inspection so consider that in your purchase price.
With that said I seen an incredibly clean GQ with 200k on the clock in duel fuel for $2500... It would take some driving for me to break even on the diesel purchase price!

[warner01]

I think its a lot to do with who fit the gas also. Ive converted all of my cars to gas and as for economy theres not a big difference in kms per lt gas vs pet. yet its still way cheaper than pet. A crappy gas system will be just that on your car. i have tried lots of different types of gas and theres really only 3 good systems out there.
On a recent trip to the flinders i drove my GQ ( yes its not stock sue to the v8 but anyway. ) up to the ranges with my brothers in tow with a diesel 75 series and a 2004 prado gas pet v6. we alll worked out to be pretty close in cost per km with the diesel being much slower to do it.
In saying all this its down to personal preferance and what you want. Id still go a turbo diesel if i could but i cant get past that v8 sound so petty for me.

[alterastro]

Sorry to resurrect an old thread, but I've had my TB48 duel fuel for about six months now. I'm in the Uk and as far as I know it's the only TB48 in the country...

Thing is, it has been running fine, but on a full tank of gas (105lt tank, 80lt when full) i'm only getting 150 miles (240km) from it. Doesn't seem much better on petrol. Now it is lifted with winch and bumper etc but does it sound like there is something wrong? I just assumed, with nobody over here to compare it with, that's the best I could expect!

If something does sound wrong, where should I start looking?

Cheers

Nick

[threedogs]

Sounds right a big thirsty 4.8 would drink as much as my 350 Chev troopy.
I returned figures of about 150ks from a 90ltr tank until I installed a larger
120ltr tank, was still woefull

[mudnut]

Have a read of the small section dealing with running LPG on this thread.

http://www.nissanpatrol.com.au/forums/showthread.php?28517-RB30-Facts-Figures-and-Helpful-Hints

There are so many variable factors which can cause high fuel usage on a duel fuel engine. Getting it tuned by an expert may help.

[BigRAWesty]

The problem with most dual fuels is you cant tune 100% to both.. you have to compromise..
A mate of mine has a tb45 dual fuel and is going full petrol..
He only has the 40l petrol tank so has bugger all range..
His range will near double once we fit the 90L rear tank as he only has a 90L gas tank..

[mudnut]

Yes, Kallen, you have hit the nail on the head. If I had a duel fuel ever again, which I won't by choice, I would set it up as a dedicated gas system with large gas tanks. The big problem with that is if you do run out of gas you are stuffed.

[lucus30]

The problem with most dual fuels is you can tune 100% to both.. you have to compromise..
A mate of mine has a tb45 dual fuel and is going full petrol..
He only has the 40l petrol tank so has bugger all range..
His range will near double once we fit the 90L rear tank as he only has a 90L gas tank..

Just did mine. 2 new tanks a 75 litre and 145 litre
I hated the gas. I say gas is for bbqs not cars

[Bob]

Well Guys I have a 4.5 Dual Fuel and obtain the following

105 Useable Litres of Gas using 18 Litres per hundred which equates to 583 K's
35 Litres ULP using 16 Litres per hundred K's 218 K's
Total of approx. 800 K's (These figures are for Highway Cruising)

Gas is 50cents a Litre in Bendigo which costs $9 per 100 K's of Motoring on Gas so total cost to fill a Tank of 105 Litres is $52.50

Towing our Caravan Gas usage is 25 Litres per 100 K's equates to 420 K's

I had the Head Ported out to allow for better breathing which improved fuel consumption greatly
More than happy with Gas

[threedogs]

The problem with most dual fuels is you can tune 100% to both.. you have to compromise..
A mate of mine has a tb45 dual fuel and is going full petrol..
He only has the 40l petrol tank so has bugger all range..
His range will near double once we fit the 90L rear tank as he only has a 90L gas tank..

Should be able to fit a 120ltr tank in a Patrol YES???
its only 998mm between the chassis rails yes??
You really want sequential injection for a better burn and efficiency

[lucus30]

Well Guys I have a 4.5 Dual Fuel and obtain the following

105 Useable Litres of Gas using 18 Litres per hundred which equates to 583 K's
35 Litres ULP using 16 Litres per hundred K's 218 K's
Total of approx. 800 K's (These figures are for Highway Cruising)

Gas is 50cents a Litre in Bendigo which costs $9 per 100 K's of Motoring on Gas so total cost to fill a Tank of 105 Litres is $52.50

Towing our Caravan Gas usage is 25 Litres per 100 K's equates to 420 K's

I had the Head Ported out to allow for better breathing which improved fuel consumption greatly
More than happy with Gas

But what do you do in places you can't get gas? Also I've noticed heaps of servos are no longer supplying gas

[alterastro]

Thanks for your replies guys.

So if my math is correct I'm drinking 33litres per 100km (in uk money I'm doing 150 miles to a full tank of gas - 80litres) which judging by posts on here is way high!

In the Uk petrol is around the £1.08 per litre (au$2!), yes, really! You don't know how lucky you guys are! Gas is about half price so you can imagine I'd like to get as many miles as possible!

But where do I start?

Cheers

Nick

[jay see]

Nick you haven't told us what type of system you have. I'm running a direct injection (stag) system and am getting about the same as Bob when he's towing, but I'm not, so I still need to improve.

If you are due for new spark plugs go for a gas plug, they're a colder plug (I think).

I've been told that the TB patrols like to breath. I'm wanting to go with extractors and a 2 1/2" exhaust.

Other thing would a good tune if you can find someone how knows what they are doing..

What type of driving are you doing, motorway of city. That makes a big difference.

Good luck.

[alterastro]

Hi Jay See
All I know is that it's Stag sequential, but don't know the particular model.

I had new plugs (NGK LPG) fitted about 6 weeks ago and have had problems since (see my other thread) - basically running very rough on gas at times but not always - mainly under load, I.e. Steep hills or towing. Much better or no noticeable problems on petrol. First stop is new throttle body and inlet manifold gaskets which weren't changed at the time as they take silly long times to get from Japan. They should arrive in the next few days and will hopefully cure the rough running/missing problems.

But fuel consumption is no better or worse since the new plugs so I've gotta look elsewhere. I'm gonna get the gas system serviced and checked but my nearest garage is about 100km away! Next step I guess is engine tuners. Lots around that want to chip it or remap the eck but I don't think that's a good move. Need to find an old school tuners me thinks!

Thanks again

Nick

[alterastro]

Sorry, forgot to say, mixed driving, motorway, town, off-road!

Also forgot to say I've been getting O2 sensor errors pop up, usually after driving in wet stuff. I don't think they are faulty as if I clear the code, it's fine until the next wet stuff. Hoping there is an inlet manifold leak which is confusing the sensors + water = EML and code.

[jay see]

Hi Jay See
All I know is that it's Stag sequential, but don't know the particular model.

I had new plugs (NGK LPG) fitted about 6 weeks ago and have had problems since (see my other thread) - basically running very rough on gas at times but not always - mainly under load, I.e. Steep hills or towing. Much better or no noticeable problems on petrol. First stop is new throttle body and inlet manifold gaskets which weren't changed at the time as they take silly long times to get from Japan. They should arrive in the next few days and will hopefully cure the rough running/missing problems.

But fuel consumption is no better or worse since the new plugs so I've gotta look elsewhere. I'm gonna get the gas system serviced and checked but my nearest garage is about 100km away! Next step I guess is engine tuners. Lots around that want to chip it or remap the eck but I don't think that's a good move. Need to find an old school tuners me thinks!

Thanks again

Nick

Throttle body may just need a clean, as it builds up carbon. Also have a look at the maf , that may need cleaning.

What about tappet adjustment, when was that last done.

Just throwing out ideas.

I've got the same system. If you want I could give you an email address to the guy that tunes mine. Long shot but he may have contacts over there. He plugs it up to his laptop and tuned it that way.

Will have to have a look at your other thread when I get home.

[alterastro]

Cheers. You would hope that when they removed the throttle body to do the plugs they would've cleaned it! But I'll make sure to ask them to do it when they do the gaskets.

Tappets - no idea - possibly never. Do they need doing at a certain interval? It's done 73,000 miles btw - about 117,000km so fairly low for its age (2003).

[jay see]

Tappets generally every 20,000 km.

[garett]

if your running a 4.8 tappets are a bucket and shim jobbies.(at least the one i did) check em but changing em is not a quick job. 200 000 before we had to change them. but that is a vapour gas system. oh on other gas notes incorrect plug gap can cause misfires under load. (also had 4 out of 6 brad new plugs fail within a week) and leaking manifold can cause lots of problems. back fires can destroy your intake piping too so be careful. just a couple things i've found. and no way would i own a gas car.

[CPOCSM]

Have owned the tb42e with mixer type LPG of 90 useable litres and a 45 litre petrol sub tank and returning the following consistently

LPG is around 19.5l/100km on the highway and 21.5l/100km city
Petrol is 17.9l/100km on the highway and nearly 20l/100km city

Gas is anywhere between 450-485km per tank depending on driving conditions and petrol around 290-325km per tank. Great on the highways on the LPG and can get from Toowoomba to rocky with fuel to spare.

[bazzaboy]

After owning my 2014 Y61 for over a year now, and being my first "modern diesel" 4wd since an old landy a few life times ago, I think my next 4wd will be will be a petrol job. Although I love the off-road capability of the Patrol, I don't like it's inconsistent economy, lack of power, and potential repair costs ( bad fuel repairs - fuel pump ).
After owning two120 series 4lt petrol Prados, that potential repair costs were minimal and fuel economy was good, not great, but consistent, I just don't think owning another modern diesel is a viable choice for me.

My previous Prados consistently returned about 14-15ltrs when towing, 4wdriving, Hwy or urban driving, giving good range with 180lt fuel capacity.

Now that I have virtually retired and have bought another vehicle for daily use, the cost of running my Patrol has reduced significantly as it will be only used for trips and not a daily driver, so I will be keeping it for some time.

If, and when I decide it's time to get another one, it will be a petrol 4wd.

Bazza

[npw112]

I have a '98 4.5 with an 80L lpg tank an a 50L petrol and I get 250kms around town and about 300 on the highway.

I don't even run the thing on petrol as my trips in it are to the South Coast (200kms each way and heaps of LPG availability) and when I go out to the tracks it is usually about 150km round trip. The range is fine for my purposes.

Wasn't prepared to fork out for a 4.2TD for my first 4x4 but wanted a bit of grunt for towing my boat so the 4.5 on gas was the only real choice.

In saying that when I get a newer Patrol, it will be a TD for sure.

[Bigcol]

Thanks for your replies guys.

So if my math is correct I'm drinking 33litres per 100km (in uk money I'm doing 150 miles to a full tank of gas - 80litres) which judging by posts on here is way high!

In the Uk petrol is around the £1.08 per litre (au$2!), yes, really! You don't know how lucky you guys are! Gas is about half price so you can imagine I'd like to get as many miles as possible!

But where do I start?

Cheers

Nick


if your still having problems finding someone to tune your beastie..........

have a look for a Forklift service place........ most of the Komatsu & Cat forklifts (4-8T) use the TB48
as they service he Gas forklifts, they will be able to point you in the right direction for someone to service it for you

[mudnut]

I don't even run the thing on petrol.

There is your problem, as you need to run petrol too keep the carby components from drying out. It is recommended to start the car on petrol at least once a day.

I think you need to put a carby kit in and see if that helps. Then get it tuned as Col suggested.

Have a look at the section dealing with lpg in this thread:

http://www.nissanpatrol.com.au/forums/showthread.php?28517-RB30-Facts-Figures-and-Helpful-Hints

[Bigcol]

mine was a daily driver (1989 GQ TB42 petrol/Gas)
1 day a week, I would run it on Petrol for the trip home from work

mine was professionally tuned (by a guy who used to race) as I spent most of the time (6.5 days out of 7) on Gas
hence why the Kws were so similar (96Petty / 93 Gas) but I could still spin an 11R15 on a dry bitumen road in Gas when I wanted to

mine was a Carby, with a Sprint Gas Mixer on it
67245

the guy around the corner from me had no end of trouble with his,
he had to start his in Petrol, wait until it warmed up before he could flick it to Gas
to go from Gas to Petrol, he had to be stopped on the side of the road, as it would not switch over right away - as he was going to "fred Nerk Automotive" to get it tuned - as a Gas tuner, he made a great fisherman


mine
start on Gas........
run on Gas.......
flick it from Gas to Petrol while on the move
flick it from Petrol to Gas while on the move

yes I had electronic ignition - (played with an Automag Magneto for awhile, but without success)
yes I had the rotor modified
yes I had top quality Leads
yes I had top quality Gold Tip Plugs (the BPR6E were about $2.20 each I think at the time, and the ones I was getting were around the $10.00 each mark from memory)
yes I had a guy who used to race Gas Cars do my tuning for me - was never successful when I did it
yes we used the proper Lambda gauges to get it running sweet

[LostBenji]

Just my 2 cents to fuel the discussion... lol

Now I don't run gas, I am happy with me 1000+ KM's on stock tanks. I do however remember the good old days of running performance cars and while I was a gasser, I did start down the path after seeing many high-performance engines running on BBQ fuel.

Gas needs the following to be efficient:

A very different ignition curve/profile to petrol.
Higher cylinder pressures through more boost or high compression ratios.
Stronger spark to accommodate the higher cylinder pressures and bigger plasma ball on plug gap.
Good quality mixer and vapouriser if using vapour. (Gas Research were the GO back then)
Smart ECU tuned for gas.
Good sealing intake valves, clean induction tract and free of leaks.
Short induction tracts to avoid bang-bang if it does backfire.



I am looking at possible project to sell my ride (or look at conversion) and step into a GU with a TB45 or TB48 Manual with intentions of forced induction. Yes, I would be going full straight-gas, no petrol.
I don't bother with the "What if you run out of fuel" lines, not the first time a 9KG BBQ cylinder has been used to fix the issue of piss-poor-planning before doing a trip.

The biggest anti-gas reason I see, high prices. 85c/L up here.