LPG math

m4rkw · May 1, 2019

6 hours ago, Herbie said:

What does it say on my valve cover? I'm sure I can see "VVT-i" there - or do I need to go to Specsavers?

Yep certainly does. Maybe you didn’t have the car long enough to see the wear? I dunno. Or maybe your engine has hard valve seats. I don’t think Prins would put a document like that out without there being some basis to it.

Herbie · May 1, 2019

The car previous to our RX300 was a Nissan Maxima QX, which also had a VVT-i engine.

We bought it with 22k on the clock and had it converted within a month of buying it, then went on to do more than 115k on LPG without a single problem that could be attributed to LPG.

You're overthinking it.

Yes, some cars may have problems but by far, the greatest majority don't. People don't tend to go on forums just to say 'Hey, my car's running great'; they usually go on because they have a problem and they're looking for a solution. Read enough forums and you'll think 'This is a disaster' but for every one problem on a forum there'll be hundreds or even thousands without problems in the real world.

That one report on the Prinz list is for the RX300 with the 1MZ-FE engine which yours isn't and the Toyota Camry (your engine) isn't even on the list.

Anyway, with the greatest of respect and no offence meant to anyone, I'm now bowing out of this topic because you'll either do it or you won't. All I can offer is my real-world, personal experience of saving lots of money and always having a big grin on my face when I was filling up, and that I would always use Flashlube.

And with that.... I'm gone 😉

Richard Fixter · May 1, 2019

Why not head over to the lpg forum web site and ask your questions there,there are many installers and knowledgeable people.

m4rkw · May 1, 2019

23 minutes ago, Richard Fixter said:

Why not head over to the lpg forum web site and ask your questions there,there are many installers and knowledgeable people.

That’s a good suggestion, thanks, I will do. I went to see my local installer today and he seemed pretty confident it’ll be fine if i use flashlube.

Rx300-SE · May 7, 2019

On 4/27/2019 at 6:31 PM, m4rkw said:

I have a 2006 Harrier with the 4-cylinder engine. Today I did 86 miles and tracked the mileage with fuelly which showed 23.5mpg. This was a combination of urban driving, cruising at 50 through the average zones on the M23 and cruising at 83 for most of the rest of the motorway. All together should be a fairly good average of the kind of driving I tend to do.

So on petrol at £1.28/L 23.5mpg gives 0.258p/mile

LPG would be a 20% efficiency loss (could be less but lets assume 20%) so I should see around 18.8mpg, and at £0.62/L that works out to 0.15p/mile.

I do about 9000 miles/year so on petrol 9000 x 0.258 = £2322. On LPG 9000 0.15 = £1350.

I was quoted £1275 to convert the car by a local specialist. For a saving of £1000/year on fuel (as a conservative estimate) this seems like a no-brainer.

Apologies for my late reply,

I've been running a Lexus RX300, 04 Plate on LPG since 2008. 21k miles when I converted it at a cost of £1500** Prin LPG system + flash lube , (80ltrs under carriage LPG tank), Its been very economical running this car. and its been trouble free, My view is if you want to convert any car make sure its at least 4 years old (newish) so you can keep it for long to recoupe the cost of conversion. Converting a 13 years old car to LPG is waste of time and money...

I understand the case of accident and insurance have to pay you off, in that the investment is lost............ but hmmmmmmmmmm everything come with its own risk

Its been a very good experience for me and I’m planning to do a new conversion soon on a 2014 Rx 450h using the same company medway dual fuel

Their service was outstanding and Ill recommend them

A full LPG tank give me 350 miles on motorwayand about 280 miles urban

m4rkw · May 7, 2019

3 minutes ago, Rx300-SE said:

Converting a 13 years old car to LPG is waste of time and money and you may never recoup cost of conversion if it starts developing non LPG related problems....

I don't see why it would. My car is in very good condition and only has 90k miles on it. I'm expecting to get at least another 100k out of it.

Rx300-SE · May 7, 2019

1 hour ago, Rx300-SE said:

Apologies for my late contribution,

I've been running a Lexus RX300, 04 Plate on LPG since 2008. 21k miles when I converted it at a cost of £1500** Prin LPG system + flash lube , (80ltrs under carriage LPG tank), Its been very economical running this car. and its been trouble free, My view is if you want to convert any car make sure its at least 4 years old (newish) so you can keep it for long to recoupe the cost of conversion. Converting a 13 years old car to LPG is waste of time and money...

I understand the case of accident and insurance have to pay you off, in that the investment is lost............ but hmmmmmmmmmm everything come with its own risk

Its been a very good experience for me and I’m planning to do a new conversion soon on a 2014 Rx 450h using the same company medway dual fuel

Their service was outstanding and Ill recommend them

A full LPG tank give me 350 miles on motorway and about 280 miles urban

Herbie · May 7, 2019

1 hour ago, Rx300-SE said:

I’m planning to do a new conversion soon on a 2014 Rx 450h

I've been running LPG cars for the last 15 years or more but only on petrol-engined cars.

I know that it's technically possible to convert hybrids but I really would not do it. The RX450h (like all hybrids) is an extremely complex system and I really think that adding yet another layer of complexity to it is really going too far and just asking for trouble.

I love LPG and I'm almost evangelical in spreading the word about it, but I would never convert a hybrid.

Bluesman · May 7, 2019

3 hours ago, Herbie said:

I've been running LPG cars for the last 15 years or more but only on petrol-engined cars.

I know that it's technically possible to convert hybrids but I really would not do it. The RX450h (like all hybrids) is an extremely complex system and I really think that adding yet another layer of complexity to it is really going too far and just asking for trouble.

I love LPG and I'm almost evangelical in spreading the word about it, but I would never convert a hybrid.

Preach on brother.

m4rkw · May 8, 2019

I'm probably going to do it, just waiting for my local installer to get back to me about the tank size etc. He measured the space and said it'd probably take about 60L (actual fuel capacity not the size of the tank). I also asked him to check with BRC that there aren't any specific known issues with my engine that they're aware of, although he was fairly confident it'll be fine.

Herbie · May 8, 2019

Sounds like he's looking to fit a 75L tank (80% of 75 = 60L).

Although yours is a Harrier import I'd assume the wheel sizes should be the same as our RX300s so he should be able to fit an 85L tank in there like mine was. I know we're only talking 10L difference but the more you get in, the longer it lasts.

Something else to mention is where you want the filling point located. Petrol pump hoses are usually quite long and even if you pull up at the 'wrong' side for the filler it'll usually still reach, so no problem. LPG filling hoses aren't anywhere near as long and are often attached to the pump with a steel cable, so you have to pull up at the correct side because the hose just won't reach otherwise.

One way round this is to do what I did and get the filler point centrally mounted under the back bumper. It means that you can fill from either side (so don't need to wait in a queue to get the pump and filler aligned if other cars are near) and it also means that the installer doesn't have to cut a hole in the bodywork.

Farnham Dave · May 16, 2019

On 4/27/2019 at 6:31 PM, m4rkw said:

I have a 2006 Harrier with the 4-cylinder engine. Today I did 86 miles and tracked the mileage with fuelly which showed 23.5mpg. This was a combination of urban driving, cruising at 50 through the average zones on the M23 and cruising at 83 for most of the rest of the motorway. All together should be a fairly good average of the kind of driving I tend to do.

So on petrol at £1.28/L 23.5mpg gives 0.258p/mile

LPG would be a 20% efficiency loss (could be less but lets assume 20%) so I should see around 18.8mpg, and at £0.62/L that works out to 0.15p/mile.

I do about 9000 miles/year so on petrol 9000 x 0.258 = £2322. On LPG 9000 0.15 = £1350.

I was quoted £1275 to convert the car by a local specialist. For a saving of £1000/year on fuel (as a conservative estimate) this seems like a no-brainer.

There's extra annual servicing to pay for, I believe