frog hopper
Well-Known Member
And you got a fist full of green stamps, it's how I got my first set of tools. Not great quality but better than nowt.
And you got a fist full of green stamps, it's how I got my first set of tools. Not great quality but better than nowt.
I have run my 2000my 4.0 V8 on gas for 14 years since I had it converted as soon as I bought it at 27K miles. It is now on 92K. It has Zavoli sequential conversion. On conversion it had 2 40ltr lpg tanks fitted in place of the fuel tank and a 36ltr auxillary petrol tank. When filled it held 72ltrs of gas due to the space left above the gas. It starts on petrol and changes to gas on warm up. I have checked the distance travelled on the gas and it is 12 to 14mpg and can be under 10 towing in the wind. But that is not accurate as it used petrol for the first mile or so. I found the 72 ltrs does not give you enough range on a fill so you are always looking for LPG. I added a further 27ltr tank under the sill where the air compressor goes. (mines on coil springs) it now holds 92ltrs full. Towing the caravan its range is around 230miles on the motorway. Solo it will do over 300 miles on a fill. I cannot comment on petrol consumption as it runs on gas. Interestingly I have used it in France using the GPL-C and it runs better, the lpg is a different mix and contains more butane than UK. When you disconnect the filler hose in France you dont get a puff of gas, it drips on the floor and looks like milk! then it evaporates. We did a test while in France on the flat 56mph roads in the Vendee and it returned over 18mpg on this fuel. If you are buying gas roadside at 69.9p and unleaded is £1.16 then the saving is not massive. You have to use Gas bottle suppliers with a tank and pay less than 60p a ltr. All mileage driven to fill up is also lost benefit. Also gas bottle suppliers are only open working hours so are not always open. I compare the running cost against diesel not petrol because that is the alternative. From what I am told it compares or betters the TD5 on running cost. Would I convert another ? probably not now Shell have closed many sites I used when away from home. I pay 58p per ltr a mile from home for gas. As for fitting LPG cylinders upside down you may as well run on petrol if you run out of gas until you get to the next refill site. Also you have to factor in the conversion cost and how many miles you need to cover to recover that cost. Filllpg website is essential now garages are removing it.The petrol tank is 18gal so around 81 litres.
360 from 18gal is around 20mpg for petrol
Not too bad
Henry_b
Think outside, no box required.
Mine has a 84LTR Tank and it did around 150mi from that tank at around 10MPG which when I realised it would easily do 21MPG on petrol LPG didn't make much sense, and also considering LPG in my area is out of my way and not that much cheaper than Petrol it doesn't make sense.
I think your 20mpg on petrol is possible but not the norm. The only way to get a accurate check is to brim the tank up the neck to the top. Note your mileage, run your distance refill to the brim, note your mileage and amount of litres used to fill
Divide the litres by 4.546 to get gallons then divide the mileage by the gallons. Also its possible to get short filled at the pump as there is an allowable error on an exact amount delivered. I understand the latest digital pumps are that accurate they can be set to the minimum delivery. I would expect your petrol mileage as 16-18 to the gallon, where on LPG 12-14 is the norm. I think 75% on economy and 80% on performance against petrol is accurate for LPG running. Adding LPG tanks to the motor increases the weight of the vehicle. The oil in the engine does stay cleaner when running on LPG. If you can fill locally the running cost on LPG does better Petrol but not half the cost as some claim. The only reason for converting to LPG is to reduce running costs. I dont know how many miles you need to cover to recover your conversion costs. Mine does not have flash lube fitted but I am told it is a must on post 2006 engines to stop exhaust valve recession.
Divide the litres by 4.546 to get gallons then divide the mileage by the gallons. Also its possible to get short filled at the pump as there is an allowable error on an exact amount delivered. I understand the latest digital pumps are that accurate they can be set to the minimum delivery. I would expect your petrol mileage as 16-18 to the gallon, where on LPG 12-14 is the norm. I think 75% on economy and 80% on performance against petrol is accurate for LPG running. Adding LPG tanks to the motor increases the weight of the vehicle. The oil in the engine does stay cleaner when running on LPG. If you can fill locally the running cost on LPG does better Petrol but not half the cost as some claim. The only reason for converting to LPG is to reduce running costs. I dont know how many miles you need to cover to recover your conversion costs. Mine does not have flash lube fitted but I am told it is a must on post 2006 engines to stop exhaust valve recession.
+1. In my experience the 4.6 does about 18 mpg on petrol. Of course, it depends what sort of driving you're doing. Longer cruises do better.
Henry_b
Think outside, no box required.
The Sagen/Gems V8's will do 16-18mpg on petrol which is about normal on LPG with a properly calibrated system it should see 14-16mpg but it is possible to get worse..
The Thor on the other hand without any faults should easily do 20mpg mine has done an average of 20mpg over 1200mi and I don't hang around.
even towing i've not been able to get it below 12mpg
On LPG the Thor should do 15-17mpg again if it is calibrated, I tend to rag mine on LPG so the figure is always poor
On Multipoint systems the LPG slaves off the Petrol injection system, so if there is a fueling issue with the petrol side it will be the same on LPG.
The misconception of terrible MPG only applies to those engine with faults, Lambda sensors not switching is the most common fault along with the incorrect sensors being used.
Gems uses a 5-0V Titania sensor while the Thor uses a 0-1v Zirconia sensor this is often not realised and the MPG will be knocked off by quite a margin
As will the running/performance in some cases.
Mine was averaging about 14 locally with minimal motorway mileage (Gems 4.6), but interestingly during Nov-Dec, I was doing daily trips Langley to Reading & occasionally Newbury, but always at 50mph due to the M4 roadworks. Didn't check it properly, but the MPG shown in the dash as generally 20-21 most weeks. Over Xmas it's now back to 15 as expected.
Not worth doing LPG as I generally average <<3000 per year, & my nearest LPG station is Hayes and wrong direction !!
as expected. Not worth doing LPG as I generally average <<3000 per year, & my nearest LPG station is Hayes and wrong direction !!
