GPL for Z4M Coupé

[dalmat]

Heey all,
my question might be stupid, but let me explain.
I have bought this car for the simple reason of giving me plaisure during weekend when off work.
During saturdays and sundays I normally drive for 1000kms up and down from monte carlo to italian alps of courmayeur.
1000kms per weekend means 4000kms per month.
Avverage consumption is between 9 and 11L/100kms.
I need 2 full tanks and 30€ to accomplish my journey.
55L X 1.40€ = 77€ full tank X 2 = 154€ + 30€ = 184€ :!:
Than I have to add highway fees... :headbang:

This cost encourages to think GPL solution....
Is this reasoning really out of mind?
Do you have any experience?
Thanks for your time.
dalmat

 

[spokey]

What do you mean by GPL?

 

[Color]

Hi dalmat,

would you mind explaining the term GPL ?

EDIT: Let me guess . . . : Gaz de Pétrole Liquéfié = some kind of liquid Butane/Propane gas mixture? Also called LPG in english . . .

 

[spokey]

:headbang:

Z4M with LPG?

Computer says NO.

 

[dalmat]

GPL = gas/fluid petroleum liquefy.

Your garage install tank gas in the back of your car of 20/30/40/50 L.
The price for a L is 0.60€ and car loose only 5% of engine perfomances.
343 - (5%) = 326 horse power.
To full tank: 0.60€ X 55 = 33€

What do you think?
dalmat

 

[Andy]

i wish i could do 1000 km (620m) on 2 tanks of fuel.. would have thought your fuel would be cheaper though, as mine costs about £55 to fill up..

i came up with a very simple answer.. i bought a 406 HDI which does 650m on 90€ of fuel... i wish there was another way around it. did 400m in the 406 last night.... so the //M is parked outside my office unusually this morning =)

 

[dalmat]

Andy,
for 1000kms I need 2 full tanks and 30€ more...
Rather than that I do not get your message... :?
dalmat

 

[Andy]

sorry dalmat i was going off-topic.

1000kms on 2 full tanks seems like sensible driving to me, well done!

I don't think you can do anything about running the Z4M on different fuel though.

 

[carl]

If you mean LPG, I can't for the life of me think where you'd put the tank without using up all of the boot (trunk) space.

 

[dalmat]

Carl,
There are many tanks available on the market: 10/20/30/40 L.
Looking trunk space I would rather say 20/30 L.
The new tank has the same space as per gasoline tank that you have at the back of your car.
Is this crazy thinking?
If I have 2 weeks of from work I would have problems anyway in putting my bags inside, immagine bags from my girl
dalmat

 

[dalmat]

Andy,
1000kms I need 2 tanks and 30€ (21L) more = 131L
dalmat

 

[Jason White]

Carl,
There are many tanks available on the market: 10/20/30/40 L.
Looking trunk space I would rather say 20/30 L.
The new tank has the same space as per gasoline tank that you have at the back of your car.
Is this crazy thinking?
If I have 2 weeks of from work I would have problems anyway in putting my bags inside, immagine bags from my girl
dalmat

You can have a doughnut tank fitted which has the petrol tank within the LPG tank which will alleviate and space issues plus the higher calorific value of LPG (GPL) compared to petrol means you'll struggle to see a 5% decrease in power particularly with modern injection systems. However, I'd temper your calculations by saying that you'll see an overall cost saving of around 30% based on UK prices but that's with higher duty added so Italy may be cheaper.

 

[carl]

Doughnut tank is no good -- it goes where the spare wheel goes. But the Z4M has no spare wheel.

Standard fuel tank is 55 litres, which already gives a crappy range. I'm averaging 23 mpg at the moment, knock off 10% for the lower calorific value of LPG and that makes 21 mpg. Then factor in that you can only fill an LPG tank to 80% full, so you're looking at a 30 litre tank holding 24 litres, i.e. around 5 gallons at 21 mpg. That gives a range of 105 miles if you run the tank dry.

I don't know what the situation is where you are, but in the UK you could waste that 100 miles trying to find an LPG station :rofl:

Note: LPG is lower calorific value (less bang per buck) than petrol. The only thing in its favour is higher RON (around 102) but you only benefit from that if your car is mapped for 102 RON fuel, which usually it isn't in a dual-fuel configuration. Some high-end ECUs (e.g. Motec) support switchable maps -- I've always wondered why someone hasn't done an LPG/petrol switchable map. Late-model TVR Cerberas used to have a 95/98 RON button on the dashboard.

 

[Top pup]

Given that it doesn't do your engine a lot of good in the long run, combined with the amount of general butchering done to your car to fit it in the first place, I'd think I would give the LPG idea a miss on the Z4M if I was you.

 

[tehdarkstar]

What? LPG for the Z?

I'm sorry man, but if high running costs are an issue for you maybe you should consider another car. An M car is always going to be expensive to run. Modifications will just spoil the very first reason why someone would buy it, which is the driving enjoyment (that's my opinion).

 

[Jason White]

Doughnut tank is no good -- it goes where the spare wheel goes. But the Z4M has no spare wheel.

Standard fuel tank is 55 litres, which already gives a crappy range. I'm averaging 23 mpg at the moment, knock off 10% for the lower calorific value of LPG and that makes 21 mpg. Then factor in that you can only fill an LPG tank to 80% full, so you're looking at a 30 litre tank holding 24 litres, i.e. around 5 gallons at 21 mpg. That gives a range of 105 miles if you run the tank dry.

I don't know what the situation is where you are, but in the UK you could waste that 100 miles trying to find an LPG station :rofl:

Note: LPG is lower calorific value (less bang per buck) than petrol. The only thing in its favour is higher RON (around 102) but you only benefit from that if your car is mapped for 102 RON fuel, which usually it isn't in a dual-fuel configuration. Some high-end ECUs (e.g. Motec) support switchable maps -- I've always wondered why someone hasn't done an LPG/petrol switchable map. Late-model TVR Cerberas used to have a 95/98 RON button on the dashboard.

A doughnut tank refers to any LPG/petrol tank combination where one tank sits within the other. You can get 60/50 litre tanks that will not only increase the range but also sit more or less within the existing footprint and given that there are around 1500 LPG retailers in the UK its certainly not difficult to get hold of - in Italy its even easier.

 

[carl]

Two into one does not go. There is no way that you can get one 55 litre tank inside another 55 litre tank, all in the space for the existing 55 litre tank...

 

[dalmat]

Tehdarkstar,
money issue is not a problem for me...
However, since I run 1000kms per week, I was questionning if this was a good or bad idea...
I have gathered plenty of information concerning LPG. I talk to a colleague which has the old m3 running LPG and he is satisfied. Not on truck because car is too heavy :rofl:
For your information, LPG does not change performance of your M at all
dalmat

 

[tehdarkstar]

Fair enough, I'm probably being a bit obtuse or stubborn here but it just sounds wrong. I wouldn't do it to my car in the same way that I wouldn't buy a diesel sports car like the ones that Audi seems to be about to release. I know that performance will be good, sometimes even better, but the only thing that would move me away from RON99 super-unleaded is bioethanol...

 

[Jason White]

Two into one does not go. There is no way that you can get one 55 litre tank inside another 55 litre tank, all in the space for the existing 55 litre tank...

The key phrase was more or less but after a decade in the industry I'll bow to your greater knowledge. :headbang: