TB42 carby/ EFI fuel economy on LPG

[dom14]

Hey guys,

Anybody out there has any statistics about the Patrol TB42 carby/EFI fuel economy on LPG(manual gear preferably)

How many kilometers per litre does it clock on average on LPG?

And how does that compare with the petrol on the same car(if dual fuel)?

Thanks for any information.

Cheers

[taslucas]

There was a fuel figures thread a while back. I can remember what is was called but maybe it's worth a search.
My tb42s was a guzzler when I used it as a daily driver. Figures up to 35 litres per hundred ks. But that was with a heavy foot. I put a flamethrower electronic ignition module and flamethrower coil on it and it made a big difference but I found that driving style was the biggest factor.

[Irish]

Bad, very bad. Before I decided to rip out the lpg gear on my rig I was getting 30 per 100.

[dom14]

Bad, very bad. Before I decided to rip out the lpg gear on my rig I was getting 30 per 100.

That's pretty bad. Was it a carby one?
There must have been some issues to get an economy that bad?

[billyj]

best ever was 13l per 100km from my tb42e, surrently averaging 22l per 100km towing 2 ton tb42e turbo

[Winnie]

I used to get around 22L/100km on my TB42e on gas

[dom14]

best ever was 13l per 100km from my tb42e, surrently averaging 22l per 100km towing 2 ton tb42e turbo

Is the 13L/100km economy from petrol or LPG?

[dom14]

I used to get around 22L/100km on my TB42e on gas

Quite close to RB30 I reckon. Mine gives 6km/L on highways and 5km/L on city driving.
But, I reckon RB30 manual one with a granny light foot like myself, should give a better economy.
I haven't quite found somebody getting an LPG economy above 6km/L yet on RB30.
Yet, there seem to be some who's getting the same economy as me on some TB42's.
Petrol or LPG economy wise RB30 is not a whole lot different from TB42, though RB30 appear to be
cheaper to repair with the abundance of RB30 engines available thanx to VL Commodore and R31 Skyline.

[Clunk]

Is the 13L/100km economy from petrol or LPG?

from dreams mate hahahahahahaha

I just don't see how that is possible, best I ever got was about 16L/100 running 31in tyres on a long journey, and up until recently on 33s, on average 20L/100 all on petrol

[dom14]

best ever was 13l per 100km from my tb42e, surrently averaging 22l per 100km towing 2 ton tb42e turbo

Try clocking it again without towing.
I reckon 13L/100km is exceptionally good & I would kill to know how to tweak my RB30 to get that sort of economy.

[dom14]

from dreams mate hahahahahahaha

I just don't see how that is possible, best I ever got was about 16L/100 running 3in tyres on a long journey, and up until recently on 33s, on average 20L/100 all on petrol

Just wondering, this general understanding of bigger wheels giving better fuel economy is 'cos bigger wheels travels longer
per a turn a of the wheel, right?

But, how bout the effect of more friction and the need of slightly heavier foot to get going with the bigger wheels?
Since switching from super tiny 29 inch to 32 inch, I haven't noticed any noticeable fuel economy gain in my RB30.

I find with the bigger wheels, it demands a slightly heavier foot to get going. Is that correct?

[Clunk]

Just wondering, this general understanding of bigger wheels giving better fuel economy is 'cos bigger wheels travels longer
per a turn a of the wheel, right?

But, how bout the effect of more friction and the need of slightly heavier foot to get going with the bigger wheels?
Since switching from super tiny 29 inch to 32 inch, I haven't noticed any noticeable fuel economy gain in my RB30.

I find with the bigger wheels, it demands a slightly heavier foot to get going. Is that correct?


no, bigger tyres worse economy....... when I said the best I got was 16l/100, i was running 31 inch tyres ........... I've fixed my typo now

[dom14]

no, bigger tyres worse economy....... when I said the best I got was 16l/100, i was running 31 inch tyres ........... I've fixed my typo now

Ok, cool. I'm bit less confused now. It's my understanding(experience) as well, that the bigger tyres cause less fuel economy, if not equal. Even though bigger tyres give longer run per wheel turn, it comes with a heavier foot on the accelerator.
All around there's no gain that I could see in mine, though I can't say for sure the fuel economy got worse.
But, I haven't clocked it recently though, so my figures are from comparison with previous times, as well as the regular habit of putting the same amount of LPG every week and zeroing the trip meter each time.
Proper test would be to fill the LPG tank to the top and run for 100km or so and refill and then doing the math.
I haven't bothered to do that yet. :)

[billyj]

my figures are all on petrol, and yes i was shocked at the 13l as well but it was on a fwy drive between werribee and sale vic (about 3 hours) usually averaged about 20l per 100km before i fitted the turbo. getting a true figure now with out towing isnt gonna happen, my patrol holds 215L and i only refuel when its empty. also atm im having to drive it daily which means towing a trailer. once my 355 stroker ute is running the patrol will be a toy again but will take a while to get a figure that doesnt include towing or heavy right foot high boost moments. and my current fuel usuage isnt really useable data for you as my tb42e has an axt turbo straped to it along with bigger retune, fuel pump, injectors etc. it made 100rwkw @4psi when initally tuned but feels a hell of a lot stronger these days with a 3" exhaust but having boost control issues as revs rise which will be sorted out once ute is tuned and driving

figures are with 2" lift on 285/75 r16 mtz's.

[dom14]

Looks like you've spent a fair bit on the truck, getting it tweaked mate. So, it's all doable for better fuel economy.
I used to drive an EA Falcon long time ago and was getting 8km/L on LPG. For a 4.1 litre engine, that was very good, even though the much lighter weight of the car helped, comparing to a heavy Patrol. At the same token, it was the most unreliable car I've ever driven. Probably 'cos the car had done enough high kms by the time I became the owner.
On the other hand, RB30 Patrol is the most reliable car I've ever driven so far. I've been lucky as well.
After I got home from two weeks long central aus trip, the starter motor died very next morning.
Another time, the head gasket blew up just down the road.
So, the Patrol has been the best thing happened so far.

[threedogs]

Your best fuel figures will be acheived with OE rim and 265S,
The 3ltr guys running 265s are getting 10/100 ,
Best I got using 285 HWY tyres at 40 psi was 12/100k.
Keep your tyre pressures at say 35 for around town and 40psi
for trips away

[dom14]

Your best fuel figures will be acheived with OE rim and 265S,
The 3ltr guys running 265s are getting 10/100 ,
Best I got using 285 HWY tyres at 40 psi was 12/100k.
Keep your tyre pressures at say 35 for around town and 40psi
for trips away

I can get 10km/L from my RB30???!!!
The wheels I got now are 235/85 s.
With the narrow tyres and constant pressure on 40psi all the time, I should ideally have the best economy.
But, I don't. It's not apparently any better than when I used to use 225/75s.

Your figures(12/100) translates to 8.5km/L.
Can that be right??!!

[taslucas]

I think Threedogs means the 3 litre diesel.

[dom14]

I think Threedogs means the 3 litre diesel.

Yeah, that must be the case.

[Clunk]

he does........... and the way I look at it, we've bought these things because they take us places where alot of other vehicles can't, not because they're frugal on fuel, if you want frugal by a Hybrid or some shit

[taslucas]

he does........... and the way I look at it, we've bought these things because they take us places where alot of other vehicles can't, not because they're frugal on fuel, if you want frugal by a Hybrid or some shit

I bought a v8 commy as a daily driver to save fuel Haha

[Chubba]

we've bought these things because they take us places where alot of other vehicles can't, not because they're frugal on fuel, if you want frugal by a hybrid or some shit

exactly !!!

[billyj]

I bought a v8 commy as a daily driver to save fuel Haha

so did i and even towing 2 ton it used less than my patrol without the trailer. be intrested to see what it does with its new 355ci stroker. just waiting on dyno tune

[dom14]

he does........... and the way I look at it, we've bought these things because they take us places where alot of other vehicles can't, not because they're frugal on fuel, if you want frugal by a Hybrid or some shit

It's got nothing to do with being frugal. Other thing is that Hybrid's are a bad idea for anybody who wants to be frugal.
I'm just collecting some fuel economy information for future adventures.
Another thing is that many of these 4Wds double as family cars, work vehicles, commuters as well. So, the fuel economy can't be ignored, unless I intend to donate money to multinational oil refineries.
Most modern cars are going turbo now, it's not all about power, it's about fuel economy as well.

[Clunk]

It's got nothing to do with being frugal. Other thing is that Hybrid's are a bad idea for anybody who wants to be frugal.
I'm just collecting some fuel economy information for future adventures.
Another thing is that many of these 4Wds double as family cars, work vehicles, commuters as well. So, the fuel economy can't be ignored, unless I intend to donate money to multinational oil refineries.
Most modern cars are going turbo now, it's not all about power, it's about fuel economy as well.
Mine is my daily and the main family car. The missus has a Honda Jazz but is a bit on the small side for the 5 of us. I am by no means well off, we struggle most months to make sure bills are paid etc. But I purchased my GQ with eyes wide open, knowing full well that it wasnt cheap to run and maintain and was most likely going to make a larger dent in our monthly outgoings. But what it has done, is enable us as a family to get out to and enjoy places we wouldn't ordinarily have been able to before, so the benefits far outway the extra costs.

And hence the reason why I don't think about economy in a big 4wd, if I did, then I would have bought a hybrid or some shit [emoji12]

[dom14]

Yeah, I agree. Hybrids are a bad idea for high testosterone guys like us.
I also have serious reservations about the fuel and monetary economy of the hybrids out there.
You can't get a low maintenance hybrid for 10k or so. So, it's a scam.
Hybrids are more about reducing emissions. I'm not too sure whether it's doing that economically either.
All that energy should have put into hydrogen or even ethanol.
If you think hybrids are frugal, ask few people who own them.
All the costs of owning a one doesn't come anywhere near frugality.

I'm opening my eyes to the world of diesel.
I like my RB30. But, I've been pointed out by the blokes who's been hardcore long distance travellers, that diesel is the way to go. Kinda treks I like to do, my RB30 may get tired one day, regardless of my careful attentions to it's quirks.
One of the reasons my GQ RB30 has been super reliable is 'cos my super attention to it.
But, it's above moderately heavy 4WD with a tiny engine to pull all that weight plus more inside it as well as along it's tail.
I have to be realistic. I don't think RB30 Patrol can be abused as much as the TBs and TDs and the later Patrols, on the heavy pulling side.

Fuel economy is important to me, 'cos at times it can be the difference between life and death.
We are simply caged in the little green coastal patches in the country.
Real country is hardly explored. And definitely not by me.

Another thing to consider is that to not using the 4wd as a daily commuter.
Unless you're a tradie who's got benefits of doing that, I would rather leave the 4wd alone and rely on car pooling, riding or a Honda Jazz or something to get around. I used to have a Barina which was super reliable and super economical, until I rolled it down a hill.
Now I ride, walk and catch public transport for work.
If you're tradie, that's out of question.
My fuel economy queries aren't about daily using of the 4wd.
It's more about frequent use of it for long distances.
I think diesel Patrols provide a good solution in the long run for that.

[taslucas]

You've basically answered all your own questions right there.
And with your super attention to detail, you should know your own fuel usage figures.
You asked for fuel usage figures but kind of got into the conversation of chasing economy which are two slightly different topics.
So one day you'll upgrade the rb30 for a diesel and not a TB42 so it's kind of redundant what fuel usage they have.
Without a lot of work the tb42's suck a lot of fuel. And if you're talking long distance travel into the outback then you don't really want a highly modified engine.

Enjoy the rb30 as a weekend weapon and have a ball doing what they're good at. Meanwhile save your dollars to get a nice reliable well set up td42 for long distance remote travel.
At the end of the day they are all luxury items so it comes down finding a balance between what you spend on it and what it gives you in return

[dom14]

Hey Taslucas,
I think I abused the word "super" too much up there. :D
Maintaining two 4WDs is beyond my means at the moment, as well as beyond my space as well.
If I'm to get hold of a TD now, I would have to let go the RB30.
Bastard has been too good to me for few years now. Not easy to let him go. :D
Besides, I was exaggerating on my "super attention" above.
I haven't been "super" all the time(I am super attentive now), yet the vehicle has looked after me pretty well.
I think RB30 is super reliable 4WD, it's just not a power horse.
It hasn't been a "luxury" for me 'cos the vehicle is 25 years old, but in terms of the running cost for me it has been, 'cos I was spending lot more to maintain the EA Falcon in running condition back then.
From what I've gathered so far, RB30 can be the most fuel economical Patrol out there, right?!
But, it's not meant to be abused with heavy loads like TBs, TDs obviously.
I will keep an eye on a Diesel Patrol, but I'm not closed to a TB, if I can get hold of EFI LPG one without lot of work needing to make it reliable.
I think RB30 is bit cheaper to maintain 'cos of the wide availability of the parts, thanks to VL Commodores and Skylines.
But, I've been noticing a reduction of available R31 skylines lately.
I used to go for Skylines to pull spare parts, but not many around lately though.

[threedogs]

If you are after economy DO NOT FIT a roof rack, keep your car clean .
Monitor your tyre pressures regularly and drive with your windows up.
Its all about the 1%ters.
Any trip I do I figure on 15/100k @ $2 a litre its about ball park for me.
Also a HWY or all terrain pattern will return better figures than chunky mud pattern
Sit on 95kph instead of any higher posted speed signs

[Clunk]

If you are after economy DO NOT FIT a roof rack, keep your car clean .
Monitor your tyre pressures regularly and drive with your windows up.
Its all about the 1%ters.
Any trip I do I figure on 15/100k @ $2 a litre its about ball park for me.
Also a HWY or all terrain pattern will return better figures than chunky mud pattern
Sit on 95kph instead of any higher posted speed signs
Mneh...... where's the fun in that [emoji12]

[threedogs]

Mneh...... where's the fun in that [emoji12]

Not me I sit on the limit, the OP wants economy,
Still see plenty sitting on the limit, lol
Might try it next trip just to see what difference it makes

[taslucas]

Hey Taslucas,
I think I abused the word "super" too much up there. :D
Maintaining two 4WDs is beyond my means at the moment, as well as beyond my space as well.
If I'm to get hold of a TD now, I would have to let go the RB30.
Bastard has been too good to me for few years now. Not easy to let him go. :D
Besides, I was exaggerating on my "super attention" above.
I haven't been "super" all the time(I am super attentive now), yet the vehicle has looked after me pretty well.
I think RB30 is super reliable 4WD, it's just not a power horse.
It hasn't been a "luxury" for me 'cos the vehicle is 25 years old, but in terms of the running cost for me it has been, 'cos I was spending lot more to maintain the EA Falcon in running condition back then.
From what I've gathered so far, RB30 can be the most fuel economical Patrol out there, right?!
But, it's not meant to be abused with heavy loads like TBs, TDs obviously.
I will keep an eye on a Diesel Patrol, but I'm not closed to a TB, if I can get hold of EFI LPG one without lot of work needing to make it reliable.
I think RB30 is bit cheaper to maintain 'cos of the wide availability of the parts, thanks to VL Commodores and Skylines.
But, I've been noticing a reduction of available R31 skylines lately.
I used to go for Skylines to pull spare parts, but not many around lately though.
condition when I had it.

It sounds like you've got an answer for every question.

A 4wd that's used for recreation and is not a daily driver IS a luxury. You don't need to have it, you want to have it.

The rb30 definitely isn't the most economical.

If you're talking long distance travel then you're talking about a heavily loaded vehicle.

So are you going to fit a TB42 and box into your existing rb30 gq or buy a TB42 patrol? Either way I'd put my money towards a diesel for long distance outback driving

[Bigcol]

I have to add


the RB30 was a silly exercise by Nissan to seem to be more economical than the TB42
however
a 2tonne car with a big slow 4.2L engine is STILL going to be more economical then a small 3.0L trying to pull the same weight
it never was nor will it ever be economical, or quick or tow with the ability of the 4.2
the reason the GQ out sold the Cruiser was because the TB42 was more powerful than the L28 in the MQ/MK and not as thirsty as the 2F engine in the Cruiser

my TB42 was gas/petrol - I used to get around 200kms out of 50L of petrol and 200kms out of 80L of Gas - towing my Van (1.9T)
it was tuned for performance on Gas (94Kw in Gas - 97Kw in petrol) @16*BTDC
it ran on Gas 90% of the time, and only occasionally on Petrol - when it ran on petrol, because the timing was for Gas - it used to run hotter than hell. - boil in 100kms constant driving

hence why I went to the TD42 GU.............
suits my lifestyle

[dom14]

Mneh...... where's the fun in that [emoji12]

Yeah, nothing like hitting 150km/h in NT highways, eh? :D

[Clunk]

Yeah, nothing like hitting 150km/h in NT highways, eh? :D
I wouldn't know, I don't go faster than the speed limit[emoji12]

[dom14]

I wouldn't know, I don't go faster than the speed limit[emoji12]

Yeah?!! I've been noticing you nose getting longer, and that isn't caused by beer. :D

I hit 155km/h near Coober Pedy, with my then GF. No cops to chase me.
Now you know why I like the desert! :D

[dom14]

I have to add


the RB30 was a silly exercise by Nissan to seem to be more economical than the TB42
however
a 2tonne car with a big slow 4.2L engine is STILL going to be more economical then a small 3.0L trying to pull the same weight
it never was nor will it ever be economical, or quick or tow with the ability of the 4.2
the reason the GQ out sold the Cruiser was because the TB42 was more powerful than the L28 in the MQ/MK and not as thirsty as the 2F engine in the Cruiser

my TB42 was gas/petrol - I used to get around 200kms out of 50L of petrol and 200kms out of 80L of Gas - towing my Van (1.9T)
it was tuned for performance on Gas (94Kw in Gas - 97Kw in petrol) @16*BTDC
it ran on Gas 90% of the time, and only occasionally on Petrol - when it ran on petrol, because the timing was for Gas - it used to run hotter than hell. - boil in 100kms constant driving

hence why I went to the TD42 GU.............
suits my lifestyle

Yeah, I agree. RB30 is half finished job by Nissan.
What they should've done was to release it with factory EFI+turbo, at least from 1992 onwards.
That way, it would've given them enough time to improve the gearbox, if that was necessary.
EFI+turbo was doing just fine with factory setting in Skylines and VLs.
So, it's a slack-arsse job by Nissan not to at least factory EFI the RB30 Patrol.

You were towing a 2 tonne van. That takes serious load on the motor, doesn't it?
No wonder the economy is so bad.
But, 200km/80L makes my jaw drop to the floor.
That's really super bad. I bet that was before you had it tuned and your TB is a carby one, and you are super heavy footed, right? :D

[dom14]

If you are after economy DO NOT FIT a roof rack, keep your car clean .
Monitor your tyre pressures regularly and drive with your windows up.
Its all about the 1%ters.
Any trip I do I figure on 15/100k @ $2 a litre its about ball park for me.
Also a HWY or all terrain pattern will return better figures than chunky mud pattern
Sit on 95kph instead of any higher posted speed signs

Yeah, but I gota have the roof rack mate. No room inside the car, 'cos I carry so many tools and spare parts.
I've been long overdue for a bigger motor, but couldn't let the troll go that easily.
It's like the "Lonely are the Brave" hero's attachment to his horse "Whiskie".
In fact, that's the name of my old troll as well. :clapping:
All these problems will be over when we invent 'Free Energy' in near future. :D

I found out the best fuel figures are around 80-90k, depending on how you tune it and whether you're pulling a trailer or not.
Lets face it, either you do 50 or 100km/h, driving is tedious. You don't get to enjoy the view around while driving.
Good reason to hire a chauffeur. :icon_bonk:;);)

[Bigcol]

I should have added that, when NOT towing my camper I was getting 400Kms out of a 80L tank of Gas

[dom14]

I should have added that, when NOT towing my camper I was getting 400Kms out of a 80L tank of Gas

I think that's around the best you could get from a carby TB42.
When you compare it with mine, there's not a whole lot of difference(or pretty much the same).
I think the main advantage with RB30 is it's probably cheaper to maintain than TB or TDs.
Not always true though, some parts are dearer when it comes to RB30( water pump, diff, etc)