Another Thread About Lpg Repairs

[brendangeorge]

Bluesman is right - sometimes you will seemingly have 3 green lights on and the next time you look the red light is on which then lasts another 100 miles. My engine was much noisier on the gas than the petrol but my guy changed something and it quietened down no end - I think it was some kind of condenser or evaporator?

Bluesman - I am pretty confident that the figures I am quoting you are accurate. Prior to getting LPG fitted I did about 25k miles and I checked my mileage on every occasion via the trip and a complete fill of the tank. I was getting 22-23 mpg on my normal around town driving (bit of a misnomer because my trip to work is 6 miles on the A19 (4 times a day). If I drove to London or Cardiff I would do the same kind of checks and sitting at an indicated 75mph for 4 to 5 hours I would get 29-30mpg. I have now done 30k miles on LPG and nothing has changed in my driving habits . If I check the mpg on the Cardiff run then I can discount the petrol as it hasn't used any so the LPG mpg is a true 21mpg. Round town at first I used to work out how many litres of petrol I had put in, work this out at 23mpg in miles and deduct this from the mileage on the trip meter. This gave me the number of miles I must have covered on gas, and this worked out at 16-17mpg. I stopped bothering with the adjustment a while ago and just use the total of the petrol and gas in litres divided into the total mileage covered - which means the LPG is getting a slight benefit of the doubt and is 17mpg.

I'm sorry to have to confess what a sad life I have :eerrrmm: but I wanted to explain why I am reasonably sure I'm getting accurate figures.

Mike

I don't doubt that your mileage figures are correct but the difference you are getting is exorbitant.

The only way for certain to get exact figures is to fill both petrol tank and LPG tank and work out a circuit of around 50 to 60 miles and make sure that the circuit ends up at the petrol station you originally filled up at and before you start the LPG circuit fill the petrol tank up so the carrying weight is the same and then do the same on LPG making sure you make a note of the mileage and then refilling your LPG at the same station and this should give you a much more accurate figure as to what your car is doing after you have the results you can take it from there.

I hope I am not teaching my grandmother to suck eggs apologies if so.

Mike

Great idea that I won't have time to try Mike! For now, I'm watching the LPG LED lights go down one at a time. So far, done over 90 miles and the first light (of four) has only just switched off.

Also, the tick over sound of my car on LPG is noticeable different (and slightly louder) than when running on petrol. Anyone else notice this?

I never take any notice of the lights on the LPG gauge as they are not accurate. I can fill up and within 20 miles one of the lights goes out which is nonsense. Most people as I am sure you do just run on the tripometer. As for the sound your engine makes I get no difference in audible engine noise and have never had a difference on any of my cars that run on LPG.

Mike.

The gas injectors will tic when you run on gas so the engine will sound different - my 430 is a little louder outside but not in the cabin.

On the fuel consumption my petrol long term average (the only real measure not Mike's race track idea) was 22mpg in 120K miles of mixed fast motorway (a lot) and town. My LPG consumtion (over 85K miles) is 65 litres (useable bit of an 80l tank) gives me 17.9 MPG - LPG has 80% of the energy of petrol so my back of a fag packet calculation looks as if the car is running well. The gain is in the price difference at the pump - 78p vs £1.35 where I live = 43% on my fag packet.

If I drove nicely I could use less fuel and do better than 43% savng on petrol. I have a 4.3l V8 that does the equvalent of 30 petrol mpg when running on LPG.

The LPG fuel indicator is a joke so I don't drive on that - I fill up on mileage.

Bren

(the only real measure not Mike's race track idea)

My idea was not a race circuit, bloody cheek, but to do a journey twice of around 50 to 60 miles in length keeping to speed limits of course that would give you a good range of driving conditions that in turn would give you some more meaningful results.

NO RACE TRACKS INVOLVED

Mike

I think you take offence too easily Mike - a long term average is the best way to determine consumption - smooth data is what you need.

Cheeky Bren :)

[Bluesman]

Bluesman is right - sometimes you will seemingly have 3 green lights on and the next time you look the red light is on which then lasts another 100 miles. My engine was much noisier on the gas than the petrol but my guy changed something and it quietened down no end - I think it was some kind of condenser or evaporator?

Bluesman - I am pretty confident that the figures I am quoting you are accurate. Prior to getting LPG fitted I did about 25k miles and I checked my mileage on every occasion via the trip and a complete fill of the tank. I was getting 22-23 mpg on my normal around town driving (bit of a misnomer because my trip to work is 6 miles on the A19 (4 times a day). If I drove to London or Cardiff I would do the same kind of checks and sitting at an indicated 75mph for 4 to 5 hours I would get 29-30mpg. I have now done 30k miles on LPG and nothing has changed in my driving habits . If I check the mpg on the Cardiff run then I can discount the petrol as it hasn't used any so the LPG mpg is a true 21mpg. Round town at first I used to work out how many litres of petrol I had put in, work this out at 23mpg in miles and deduct this from the mileage on the trip meter. This gave me the number of miles I must have covered on gas, and this worked out at 16-17mpg. I stopped bothering with the adjustment a while ago and just use the total of the petrol and gas in litres divided into the total mileage covered - which means the LPG is getting a slight benefit of the doubt and is 17mpg.

I'm sorry to have to confess what a sad life I have :eerrrmm: but I wanted to explain why I am reasonably sure I'm getting accurate figures.

Mike

I don't doubt that your mileage figures are correct but the difference you are getting is exorbitant.

The only way for certain to get exact figures is to fill both petrol tank and LPG tank and work out a circuit of around 50 to 60 miles and make sure that the circuit ends up at the petrol station you originally filled up at and before you start the LPG circuit fill the petrol tank up so the carrying weight is the same and then do the same on LPG making sure you make a note of the mileage and then refilling your LPG at the same station and this should give you a much more accurate figure as to what your car is doing after you have the results you can take it from there.

I hope I am not teaching my grandmother to suck eggs apologies if so.

Mike

Great idea that I won't have time to try Mike! For now, I'm watching the LPG LED lights go down one at a time. So far, done over 90 miles and the first light (of four) has only just switched off.

Also, the tick over sound of my car on LPG is noticeable different (and slightly louder) than when running on petrol. Anyone else notice this?

I never take any notice of the lights on the LPG gauge as they are not accurate. I can fill up and within 20 miles one of the lights goes out which is nonsense. Most people as I am sure you do just run on the tripometer. As for the sound your engine makes I get no difference in audible engine noise and have never had a difference on any of my cars that run on LPG.

Mike.

The gas injectors will tic when you run on gas so the engine will sound different - my 430 is a little louder outside but not in the cabin.

On the fuel consumption my petrol long term average (the only real measure not Mike's race track idea) was 22mpg in 120K miles of mixed fast motorway (a lot) and town. My LPG consumtion (over 85K miles) is 65 litres (useable bit of an 80l tank) gives me 17.9 MPG - LPG has 80% of the energy of petrol so my back of a fag packet calculation looks as if the car is running well. The gain is in the price difference at the pump - 78p vs £1.35 where I live = 43% on my fag packet.

If I drove nicely I could use less fuel and do better than 43% savng on petrol. I have a 4.3l V8 that does the equvalent of 30 petrol mpg when running on LPG.

The LPG fuel indicator is a joke so I don't drive on that - I fill up on mileage.

Bren

(the only real measure not Mike's race track idea)

My idea was not a race circuit, bloody cheek, but to do a journey twice of around 50 to 60 miles in length keeping to speed limits of course that would give you a good range of driving conditions that in turn would give you some more meaningful results.

NO RACE TRACKS INVOLVED

Mike

I think you take offence too easily Mike - a long term average is the best way to determine consumption - smooth data is what you need.

Cheeky Bren :)

I took offence to easy ??? My idea was to give as near accurate idea of the MPG and was not a joke. We did not want the combined MPG for Petrol & LPG spread over 86000 miles but two completely separate readings on the same day and in the same century.

Mike.

[mikeyv]

I'm not sure that constantly monitoring mpg when you run a V8 petrol of 4 litres or over, is the path to true contentment.

I've stuck mine on lpg, but beyond that I'll just fill it when needed and enjoy that lovely smooth engine for what it is.

[jpjsavage]

I'm not sure that constantly monitoring mpg when you run a V8 petrol of 4 litres or over, is the path to true contentment.

I've stuck mine on lpg, but beyond that I'll just fill it when needed and enjoy that lovely smooth engine for what it is.

Tend to agree.

Ticking is a good word to describe the slightly more noticeable engine noise when running on LPG. All relavtive of course, and you have to listen hard to hear it.

[mikeyv]

I'm not sure that constantly monitoring mpg when you run a V8 petrol of 4 litres or over, is the path to true contentment.

I've stuck mine on lpg, but beyond that I'll just fill it when needed and enjoy that lovely smooth engine for what it is.

Tend to agree.

Ticking is a good word to describe the slightly more noticeable engine noise when running on LPG. All relavtive of course, and you have to listen hard to hear it.

I have the same sound and pointed it out when picking up the car after conversion.

Injectors was what they told me as well.

Barely audible from inside the car, more noticeable outside with the bonnet up.

[mikesands]

Can't speak for BrendanGeorge, but it's a problem for me of the expectations that were created. To give you another example I have a Honda NC700X motorcycle which I bought because Honda were quoting 78mpg and many people were getting over 80 and even 90mpg. So it was a big disappointment to me that I can only get 67-ish in normal riding. But when you think about it 67 is very very good for a motorbike.

BrendanGeorge - I think your saving isn't really 43% - it's actually 29% if you do the maths. Not to be sneezed at of course but it means the payback period is considerably longer than the no-brainer that LPG conversion seems to be. (By the way LPG up here is 69pence at Asda - almost worth the drive up :-) )

Mike

[Bluesman]

Can't speak for BrendanGeorge, but it's a problem for me of the expectations that were created. To give you another example I have a Honda NC700X motorcycle which I bought because Honda were quoting 78mpg and many people were getting over 80 and even 90mpg. So it was a big disappointment to me that I can only get 67-ish in normal riding. But when you think about it 67 is very very good for a motorbike.

BrendanGeorge - I think your saving isn't really 43% - it's actually 29% if you do the maths. Not to be sneezed at of course but it means the payback period is considerably longer than the no-brainer that LPG conversion seems to be. (By the way LPG up here is 69pence at Asda - almost worth the drive up :-) )

Mike

68 down here Mike just went up from 65p.

Figures that are put out by motor manufactures and the like should always be taken with a pinch of salt.They obtain them under quite unnatural conditions and are at best a joke and worst fraudulent as you could never ever hope to achieve their figures, so don't beat yourself up to much by not being able to at least match them.

Mike

[mikesands]

Can't speak for BrendanGeorge, but it's a problem for me of the expectations that were created. To give you another example I have a Honda NC700X motorcycle which I bought because Honda were quoting 78mpg and many people were getting over 80 and even 90mpg. So it was a big disappointment to me that I can only get 67-ish in normal riding. But when you think about it 67 is very very good for a motorbike.

BrendanGeorge - I think your saving isn't really 43% - it's actually 29% if you do the maths. Not to be sneezed at of course but it means the payback period is considerably longer than the no-brainer that LPG conversion seems to be. (By the way LPG up here is 69pence at Asda - almost worth the drive up :-) )

Mike

68 down here Mike just went up from 65p. Mike

Obviously because Hampshire is a deprived area of the country with masses of unemployment and that's all they can sell it for

Just had another 'sad' moment and called up my original spreadsheet that showed capital cost of the LPG conversion being repaid in 9 months. When I fed in the real data it showed a payback of 1.8 years which coincidentally is today. Cause for celebration methinks.

Mike

[ManicMark]

I normally reset my trip & average mpg meters on mine when I fill up. when I refill I occasionally calculate how many mpg on gas compared to the recorded mpg . Its always less but only by a couple of mpg my normal weekly commute 220 miles mixed driving 24 on the meter & 22 mpg on gas. I never checked it running on petrol as mine was only on petrol for a week.

A lot depends on the system fitted mine is a brc self learning system which constantly measures the gas flow & alters the mixture.

I have 25 kw injectors ( which tic ). I think how efficient depends a lot on the system used + the installers knowledge of which system is best for each vehicle & how well its been installed & set up. I was there at the initial set up on mine it took 3 hours of fine tuning (very interesting setting & fettling the first map ).

[Bluesman]

Can't speak for BrendanGeorge, but it's a problem for me of the expectations that were created. To give you another example I have a Honda NC700X motorcycle which I bought because Honda were quoting 78mpg and many people were getting over 80 and even 90mpg. So it was a big disappointment to me that I can only get 67-ish in normal riding. But when you think about it 67 is very very good for a motorbike.

BrendanGeorge - I think your saving isn't really 43% - it's actually 29% if you do the maths. Not to be sneezed at of course but it means the payback period is considerably longer than the no-brainer that LPG conversion seems to be. (By the way LPG up here is 69pence at Asda - almost worth the drive up :-) )

Mike

68 down here Mike just went up from 65p. Mike

Obviously because Hampshire is a deprived area of the country with masses of unemployment and that's all they can sell it for

Just had another 'sad' moment and called up my original spreadsheet that showed capital cost of the LPG conversion being repaid in 9 months. When I fed in the real data it showed a payback of 1.8 years which coincidentally is today. Cause for celebration methinks.

Mike

Yes we are a deprived area. One resident in the village recently suffered dreadfully when he had to drop the price of his house by £350,000 to sell it for only £4.25 million. He was downsizing to a much smaller property costing £2.75 million.

If you can find it in your heart to send us a crust of bread we will be so grateful. Budgie again for Christmas.

Nothing wrong with spreadsheets.

Mike.

[Bluesman]

I normally reset my trip & average mpg meters on mine when I fill up. when I refill I occasionally calculate how many mpg on gas compared to the recorded mpg . Its always less but only by a couple of mpg my normal weekly commute 220 miles mixed driving 24 on the meter & 22 mpg on gas. I never checked it running on petrol as mine was only on petrol for a week.

A lot depends on the system fitted mine is a brc self learning system which constantly measures the gas flow & alters the mixture.

I have 25 kw injectors ( which tic ). I think how efficient depends a lot on the system used + the installers knowledge of which system is best for each vehicle & how well its been installed & set up. I was there at the initial set up on mine it took 3 hours of fine tuning (very interesting setting & fettling the first map ).

Have to agree. Mike

[Lexmanic]

Can't speak for BrendanGeorge, but it's a problem for me of the expectations that were created. To give you another example I have a Honda NC700X motorcycle which I bought because Honda were quoting 78mpg and many people were getting over 80 and even 90mpg. So it was a big disappointment to me that I can only get 67-ish in normal riding. But when you think about it 67 is very very good for a motorbike.

BrendanGeorge - I think your saving isn't really 43% - it's actually 29% if you do the maths. Not to be sneezed at of course but it means the payback period is considerably longer than the no-brainer that LPG conversion seems to be. (By the way LPG up here is 69pence at Asda - almost worth the drive up :-) )

Mike

68 down here Mike just went up from 65p. Mike

Obviously because Hampshire is a deprived area of the country with masses of unemployment and that's all they can sell it for

Just had another 'sad' moment and called up my original spreadsheet that showed capital cost of the LPG conversion being repaid in 9 months. When I fed in the real data it showed a payback of 1.8 years which coincidentally is today. Cause for celebration methinks.

Mike

Yes we are a deprived area. One resident in the village recently suffered dreadfully when he had to drop the price of his house by £350,000 to sell it for only £4.25 million. He was downsizing to a much smaller property costing £2.75 million.

If you can find it in your heart to send us a crust of bread we will be so grateful. Budgie again for Christmas.

Nothing wrong with spreadsheets.

Mike.

Thats nowt down 'er we have beach huts selling for 100K or more. Mind you its probably those rich sods from Hampshire who are buying them :megaangry:

[Bluesman]

Can't speak for BrendanGeorge, but it's a problem for me of the expectations that were created. To give you another example I have a Honda NC700X motorcycle which I bought because Honda were quoting 78mpg and many people were getting over 80 and even 90mpg. So it was a big disappointment to me that I can only get 67-ish in normal riding. But when you think about it 67 is very very good for a motorbike.

BrendanGeorge - I think your saving isn't really 43% - it's actually 29% if you do the maths. Not to be sneezed at of course but it means the payback period is considerably longer than the no-brainer that LPG conversion seems to be. (By the way LPG up here is 69pence at Asda - almost worth the drive up :-) )

Mike

68 down here Mike just went up from 65p. Mike

Obviously because Hampshire is a deprived area of the country with masses of unemployment and that's all they can sell it for

Just had another 'sad' moment and called up my original spreadsheet that showed capital cost of the LPG conversion being repaid in 9 months. When I fed in the real data it showed a payback of 1.8 years which coincidentally is today. Cause for celebration methinks.

Mike

Yes we are a deprived area. One resident in the village recently suffered dreadfully when he had to drop the price of his house by £350,000 to sell it for only £4.25 million. He was downsizing to a much smaller property costing £2.75 million.

If you can find it in your heart to send us a crust of bread we will be so grateful. Budgie again for Christmas.

Nothing wrong with spreadsheets.

Mike.

Thats nowt down 'er we have beach huts selling for 100K or more. Mind you its probably those rich sods from Hampshire who are buying them :megaangry:

How did you know? we try to keep it quiet. We have a very cleaver chap up in Cheshire that makes them out of old lorry pallets. Mike

[abs66]

Brilliant. Really enjoyed reading the last load of posts. Cheers guys.

[lpgdlex]

On a longish fastish (80ish as opposed to 70ish) motorway run I get about 25mpg (maybe 26) on a LPG - on petrol it would be doing about 29-30 in similar circumstances.

Around town goodness knows what it does but something pretty awful - 16 to 17 ish but I only live a mile from work and from a cold start a LS400 does about 10mpg for the first mile so it'll use a lot of petrol and LPG whatever you try in those circumstances. Awful short journey and around town fuel consumption is just something you have to accept on a 4 litre V8 whether running LPG or petrol.

I'm more than happy with 25 at 80 and I bet if I stuck to 70 it would get close to 30mpg on LPG. That's about 13-14 pence per mile which you'd need a diesel doing at least 45mpg to match.

[lpgdlex]

It wasn't brilliant before, from memory around 200 250 miles for the 50 litres. Given the cost (75p/litre) it was favourable but I'm hoping for a bit more now the system is working properly with the right regulator and new valves/filters.

That's 22.7mpg by my calculations (or just under 16p per mile at £0.78 per litre). If that is mixed driving that really isn't at all bad.

[Bluesman]

Can't speak for BrendanGeorge, but it's a problem for me of the expectations that were created. To give you another example I have a Honda NC700X motorcycle which I bought because Honda were quoting 78mpg and many people were getting over 80 and even 90mpg. So it was a big disappointment to me that I can only get 67-ish in normal riding. But when you think about it 67 is very very good for a motorbike.

BrendanGeorge - I think your saving isn't really 43% - it's actually 29% if you do the maths. Not to be sneezed at of course but it means the payback period is considerably longer than the no-brainer that LPG conversion seems to be. (By the way LPG up here is 69pence at Asda - almost worth the drive up :-) )

Mike

Just another thought, I think the other thing you are forgetting is that you have a 430 and that will always use more.

Mike

[mikesands]

if you mean in comparison with the LS400 quoted above then I can't agree as on a run on petrol we both seem to get the same (about 30mpg), but on a run on lpg he gets 25 to 26mpg at a faster speed than me where I get 21mpg.

In a moment of idle curiosity last night I researched reports of studies that were done on fleet cars where some were converted to LPG and some left on petrol, and I read some other scientific reports of comparisons between the two fuels. Without fail the independent ones quoted fuel consumptions 25 to 30% worse for LPG. The best of the ones with a vested interest tried to avoid the consumption issue and concentrated on the cleanliness to the environment and the car. I think I am convinced that the way LPG engineers are getting 'good' LPG consumption figures must be by leaning off mixture. This may be a perfectly valid thing to do when running an engine like ours on LPG but my guy obviously hasn't done it.

Mike

[Bluesman]

if you mean in comparison with the LS400 quoted above then I can't agree as on a run on petrol we both seem to get the same (about 30mpg), but on a run on lpg he gets 25 to 26mpg at a faster speed than me where I get 21mpg.

In a moment of idle curiosity last night I researched reports of studies that were done on fleet cars where some were converted to LPG and some left on petrol, and I read some other scientific reports of comparisons between the two fuels. Without fail the independent ones quoted fuel consumptions 25 to 30% worse for LPG. The best of the ones with a vested interest tried to avoid the consumption issue and concentrated on the cleanliness to the environment and the car. I think I am convinced that the way LPG engineers are getting 'good' LPG consumption figures must be by leaning off mixture. This may be a perfectly valid thing to do when running an engine like ours on LPG but my guy obviously hasn't done it.

Mike

You little book worm. It was just a thought I had. The thing to remember about any report is that we all drive differently. I drive at 77mph indicated by the in car speedo on Motorways but the Sat Nav gives your true speed which is 70mph. I live in the country and I always wait first thing in the morning for the engine to heat up especially in the winter so that she changes over to LPG almost immediately.

Mike

[lpgdlex]

Calculating exact LPG mileage is always a bit difficult as you never get quite the same amount in everytime and you can only really calculate on long journeys otherwise the petrol issue comes in.

I know pretty much on petrol at 77ish late night cruise (satnav speed not speedo although the speedo is only about 2mph out) it does 29mpg. If you keep to 70 it tops 30. I've also found the computer to be pretty much spot on when comparing with the brim to brim measures.

When the car first had LPG it was averaging about 21mpg on LPG - interestingly it didn't seem to vary much how I drove it. The mapping has since been tweaked and on the last reasonably fast 250 mile motorway run I measured the LPG brim to brim it used about £32 worth at 78p a litre so about 25-26mpg.

I've got a couple of long motorway runs to do over the Christmas break I'll probably use the Lexus for so will fill it up with LPG and run it 'till it beeps empty and report back what the odo was showing.....

[abs66]

If anyone is interested there is an app that works on android not sure about Iphone, called Fuel log that does a good job of keeping records and calculating mpg.

[Bluesman]

Calculating exact LPG mileage is always a bit difficult as you never get quite the same amount in everytime and you can only really calculate on long journeys otherwise the petrol issue comes in.

I know pretty much on petrol at 77ish late night cruise (satnav speed not speedo although the speedo is only about 2mph out) it does 29mpg. If you keep to 70 it tops 30. I've also found the computer to be pretty much spot on when comparing with the brim to brim measures.

When the car first had LPG it was averaging about 21mpg on LPG - interestingly it didn't seem to vary much how I drove it. The mapping has since been tweaked and on the last reasonably fast 250 mile motorway run I measured the LPG brim to brim it used about £32 worth at 78p a litre so about 25-26mpg.

I've got a couple of long motorway runs to do over the Christmas break I'll probably use the Lexus for so will fill it up with LPG and run it 'till it beeps empty and report back what the odo was showing.....

satnav speed not speedo although the speedo is only about 2mph out)

This caught my attention as in my car when the car speedo is showing 70mph Sally Satnav shows 64/65 mph. When Sally Satnav shows 70 mpg the car speedo is showing 76/77.

I think this goes to show that there are so many anomalies that to get accurate figures in normal road conditions is almost impossible so we have to content ourselves with what ever sums we have done and have confidence in them for ourselves.

I can get 30 to the gallon if I keep to speedo 70 in motorway conditions.

The savings that we LPG users are more than the pump price paid and how many we get to the gallon. The engine for instance will last almost forever as there are not the contaminants in LPG you get in petrol add to that what is coming out of your exhaust which is one heel of alot cleaner than again what you get with petrol, add to that the quiet satisfaction that you are driving one of the greatest cars on the road for no money, allow that smile to stretch across your face and enjoy.

Mike