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classic_rover
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Discussion Starter · #1 ·
Is anyone running a Rover 75 Connisseur SE 2.5 V6 Auto on LPG? what is the fuel consumption like versus petrol, also how reliable are they any thing to look out for when buying one?

Dale.
 

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Hi Dale, I have a 2.5 v6 and had it converted 9 months ago, fuel consumption is a bit heavier than on petrol but at 39.9 pence per litre I can indulge in the loudness pedle to my hearts content. performance wise in most conditions you wont notice much difference with modern systems. I would recommend LPG to anyone. also if your car is under 5 years old you can get the london congestion charge for free. so my conversion paid for itself in under a year.

Richard

P.S. on the reliability I have done 24,000 on gas in the last 9 months and not a single hiccup. the systems do require a service every 15,000 miles or so to change filters etc. also engines that run on lpg last longer than petrol ones as lpg does not mess up your oil like petrol.
 

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Discussion Starter · #4 ·
Richard which LPG Conversion system do you have fitted to your 75? also what is the total mileage your vehicle has travelled since new, i am seriously considering buying a 75 Connisseur and converting to LPG .

Thanks Dale.
 

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I should have said mine is an auto by the way so heavey on fuel anyway.

Kev,

I get about 250 miles from 53 litres if I am doing long runs / motorways etc.
my daily comute is 20 miles each way into central london average speed a huge 15 miles an hour! this can go as low as 190 miles, manual would be a bit higher.

Dale,

I have the "prins VSI" system fitted by dualfuel systems in woking. my car has done 42K in total most of it with me. the KV6 takes the conversion very well and I find that the auto box is not quite as "lazy" when running on gas, it seems to respond very well to the throttle.

Richard
 

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Discussion Starter · #6 ·
Richard thanks for the info very helpful, i take it 53 ltrs is the size of your LPG Tank? and you can fill it for around £22 and on a run your getting 250 miles for £22 from a 2.5 ltr engine?

Where is the LPG Tank situated on the vehicle?

Thanks Dale.
 

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Hi Dale, my tank is a 67 litre 'Doughnut' style tank mounted in the spare wheel space, remember you can only fill an LPG tank to 80% full hence the 53 to 54 litres, this is to allow for expansion etc. yes 250 miles for £22, could probably get a bit more if I tried setting the cruise at say 70 on the motorway and seeing how far I got but to be honest I like driving my car to much!

Richard
 

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Discussion Starter · #8 ·
Thanks Richard

I am on the look out for a decent 2.0 or 2.5 to LPG will let you know if i find one and how i get on with the LPG.

Dale
 

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No real reason both systems are the same type, six injectors, the gas ecu "piggy backs" the cars own so that the car is controling the gas system and its all automated, I have a small switch and led guage mounted in the car and can switch between gas and petrol at any time, the systems start on petrol until a certain temp and then switch over automaticly, similarly when you run out of gas it switches back automaticly. when I had mine done the Prins system was more advanced, but now all but the cheap systems are virtualy Identical.

Where are you dale I am in Kent if you are anywhere near and wanted to try before you buy I would be happy to take you for a test drive.

Richard
 

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Discussion Starter · #11 ·
Hi Richard

Thanks again for the info, i am actually up North in Lancashire, we do have several LPG Installers in the area and both the Prins system and Romano are available, i wondered if you had been advised to choose the prins system over another systems? there seems to be a wide variation in installation charges for the LPG systems.

I am still looking for the right vehicle there are quite a few out there although i think i might hold out for one with the Highline Sat Nav not essential but nice to have.

Regards Dale.
 

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Is my LPG system maxing out?

Hello all, been following this thread with interest and thought I'd lob this in to the pot.
I have noticed on a couple of occasions that after a bit of "spirited" overtaking, I am back on Petrol for a second or two. Yesterday I had a chance to explore further and found that at 5000rpm approx it switches over to petrol especially is provoked by a good hard prod on the throttle. I am wondering if the info from the lambda sensor if freaking out the gas system at those revs (ie. it can cope with up to 5k rpm but is not expecting anything higher) or it just canot supply enough to the engine at that rev. range? Interesting and maybe someone on the boards has an answer?

BTW, it's an MG ZT 160 V6
 

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Mine has never done this, I would suggest that when you are putting your foot down the gas system is registering a loss of pressure and temporarily thinks that it is "empty" this is probably caused by the pressure sensor having a tolerance level set to low (or high, depending on how you look at it.) I would take it back to your installer (or an approved LPG garage) and get them to check it.

My car will rev all the way to the red line under heavy load with no problems, one other thought have your LPG filters been changed? they don't need changing as often as alot of garages state but if they are very old or you have had a tank of "dirty gas" the system may be struggling to deliver enough gas.

Richard
 

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Hello all, been following this thread with interest and thought I'd lob this in to the pot.
I have noticed on a couple of occasions that after a bit of "spirited" overtaking, I am back on Petrol for a second or two. Yesterday I had a chance to explore further and found that at 5000rpm approx it switches over to petrol especially is provoked by a good hard prod on the throttle. I am wondering if the info from the lambda sensor if freaking out the gas system at those revs (ie. it can cope with up to 5k rpm but is not expecting anything higher) or it just canot supply enough to the engine at that rev. range? Interesting and maybe someone on the boards has an answer?

BTW, it's an MG ZT 160 V6
You don't say the make of your system but most sequential systems have a feature that will force a temporary switch to petrol if the LPG injector open time is greater than, say, 25mSec. This is to ensure that the engine doesn't run lean under this condition. Conversely a pressure drop below a certain point will force a "permament" switch back to petrol until reset.

However, systems will also allow a configurable change over point at which the petrol will be switched in. This is for problem vehicles and does not apply to these cars.

Either way, bearing in mind that it is not a high powered car that pushes the system to the limit, the set-up of the LPG system could be improved. It needs calibrating properly and possibly larger nozzles fitted. The latter is unlikely, however.

Tell me the system that you have and I may be able to be more precise.
 

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For those like me who are looking carefully at the numbers shown above to see if an LPG conversion is a feasible option.

I have looked at the cost recovery based on : additional servicing costs ( filters etc ), installation, 25/75 Petrol/LPG split and AA membership (no spare wheel), it looks like the cost of LPG is fully recoverable over 23,479 miles. there after it is 7.1p cheaper a mile including the additional servicing and AA membership.

The more i look at this the more it seems to make sense if you have a low milage car.
 

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Discussion Starter · #16 ·
Well heres an update, i had my heart set on a V6 2.5 SE and had done the enquirys on the Gas conversion, i was having problems finding exactly the right spec 75 in my area, some where high miles full spec or low miles with the limited spec or some priced just to high, anyway i came across a 75 CDTi Auto full spec at the right price just down the road from me, when i worked out the cost of buying a car plus gas convertion the price was about the same, after a test drive i bought the vehicle i just hope i made the right decision?

Dale
 

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mgf
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Rover 75 V6 2.5 with lpg

Hi , this is my experience with LPG. My 75 has an omvl dream system with an 80litre tank in the wheel well. During Jan 013 when I bought the car it would always switch back to petrol under very light load. Also from cold it took approx four miles[or more] to switch. We found the the thermostat was stuck open [at speed the temp needle always dropped right down to the bottom segment]. We changed the thermostat and had the system pressure filled. The temp gauge now settled on halfway pretty quick and stayed there. The lpg switched earlier but still switched back under even light loads. The matrix was not blocked and the climate worked much better I took it to Professautogas near Cardiff who had installed it . This involved lots of trips with a polish guy and a laptop that showed things seemingly ok. After nearly 5 hours there things were slightly better but still switching back under load[forget sportsmode on the autobox!
Went home to Shrewsbury and started reading up on things. We first checked the vaporizer and found it was not getting warm or only slightly. Under load it was getting cold tho not icing. We disconnected the water feed pipe to the vaporizer, placed a funnel in it and filled with antifreeze , think about a pint went in. [we left the expansion bottle cap on ]The vaporizer now gets quite warm and the system works fine in normal driving. It still switches back on heavy kick down and prolonged sportsmode, but its livable with as this is Victoria Sponge car eg sedate!. I have the mgf vvc ragtop for headbanging! From cold, depending on outside temp switching is within 1,2miles. Climate works perfectly.
The water to vap pipe is t pieced off the heating system matrix pipe feed and the outlet from the vap t`d back in after the matrix, that is, in parallel. Obviously there is still insufficient hot coolant to the Vaporizer. A fix might be to put the Vap in series eg matrix feed pipe to vap then outlet back to matrix. I have heard of 12volt electricpumps used too. Obviously matrix condition is paramount esp with the parallel setup.However we will leave things as they are and perhaps do another coolant backfill just in case there is a bubble or two left in the Vap. Mpg is about 22 in shortish gen use on lpg and keeping revs under 3000 rpm[80 to 90mph] can give say 29ish say on a 200mile run from Shrewsbury to the Medway on the motorway[not taken from the ave mpg readout on the trip comp]. As I can get lpg for 64p a litre that`s all very spiffy. The tank tho 80litre will take 63litre max which is about right.
Professgas were helpful but well not very bright in not diagnosing the Vaporizer problem. , I mean we are the amateurs. Still their system seems ok and gives good value. Lots of guff talked about you need to spend lots on a system. This one approx £900. Most systems malfunction for othere reasons than installation , fuel filters plugs leads and so on and of course coolant probs. Interesting also that the ex rover garage pressure fill here in Wem was not a fix.
So this has been just about my experience, its not a universal truth! Hope it helps and love the Rover or Victoria the sponge!
Michael
 

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I had a car converted by the very same people in Wales. Not a total success. The vapouriser was the wrong size for the car and couldn't handle the demand. After a few trips I lost my rag when he claimed it was the cars fault, not his LPG system. I ended up buying a bigger vapouriser and the software and doing it myself.

Sounds like you may have the wrong size vapouriser and it is mounted too high....hence the air lock problem. Needs to be low down. On my ZT it is behind the wheel arch inner, near the horn.

I now have a ZT 2.5 auto with a Tartarini LPG system. Works well, although I did have to renew the injectors. Getting about 24mpg on lpg with moderate driving. Not great but the auto is quite thirsty and needs a lot of throttle for moderate gains. Never switches over to gas when accelerating hard.

Will never ever take car to one of those 1 day conversion places again. Not worth the hassle...shoddy, rushed job.
 

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I had my mg zt 2.5 v6 auto done in april 2011 with the same place in wales and done about 12k and had no trouble at all with the system so far.
 

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What sort of MPG do you achieve? I do need to fit a working balance VIS. Hopefully that will get the MPG up a little bit.
 
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