LPG conversions for Prius

[semo.pz]

I'm looking for specific advice for converting a Gen 2 Prius not too far from Surrey if possible. I know that the Prius has been discussed before but there are no specifics (where was the conversion done, was it good, what kit was used throughout, etc..) . So far I've gathered that I need to look for the following points:

• The installer has to be a UKLPG certified
• The equipment must hold up to a certain standard (not all UKLPG installers use such equipment)
• The Prius can be tricky to convert because of the 0RPM state

It seems that a Prins Silverline kit installed by an approved garage should meet all the requirements. I’ve been told to save some money and not go with VSI as the Keihin injectors were designed to work with more than just LPG systems so are more expensive. Together with valve care, I’ve been told to expect to pay around £1500.

Can anyone give further advice? Should I keep shopping around or is the above the safest bet? Should I just pick the nearest Prins installer or are some better than others?

[fattyfattyboomalatty]

I work in the toyota network and itsMassively frowned upon to LPG a Hybrid, the Atkinson cycle engine just does not like it. The oficial line is simply, Dont. Sorry

[Gilbertd]

I'm looking for specific advice for converting a Gen 2 Prius not too far from Surrey if possible. I know that the Prius has been discussed before but there are no specifics (where was the conversion done, was it good, what kit was used throughout, etc..)

There have been a couple done that are returning the cost equivalent of over 100 mpg but it isn't a simple conversion and most Prius owners seem happy with the economy they get anyway.

The installer has to be a UKLPG certified

Not necessarily, the installer must do a good job and UKLPG certified unfortunately doesn't guarantee that. There are good and bad there are certified and not but while most certified installers fall into the good category, some don't and vice versa.

The equipment must hold up to a certain standard (not all UKLPG installers use such equipment)

It must be up to the job of supplying sufficient fuel for your car but the Pruis isn't exactly a high performance motor so just about any kit would be up to the job.

The Prius can be tricky to convert because of the 0RPM state

This is where it gets complicated. With most installs the reducer and injector performance is critical and the choice of controller is largely irrelevant, with a Pruis it is the other way round as, as you point out, the controller must be capable of allowing a restart on LPG (or at least with a minimum start to changeover time) and a lot have a minimum petrol run time of 20 seconds or similar.

It seems that a Prins Silverline kit installed by an approved garage should meet all the requirements. I’ve been told to save some money and not go with VSI as the Keihin injectors were designed to work with more than just LPG systems so are more expensive.

Keihin injectors are better quality, that is why they are more expensive.

Can anyone give further advice? Should I keep shopping around or is the above the safest bet? Should I just pick the nearest Prins installer or are some better than others?

Prins is a manufacturer approved install only so the chances of getting poor quality install is reduced. Contact Woody on here, he is a Prins installer who has experience of the more obscure installs.

[semo.pz]

I'm looking for specific advice for converting a Gen 2 Prius not too far from Surrey if possible. I know that the Prius has been discussed before but there are no specifics (where was the conversion done, was it good, what kit was used throughout, etc..)

There have been a couple done that are returning the cost equivalent of over 100 mpg but it isn't a simple conversion and most Prius owners seem happy with the economy they get anyway.

The installer has to be a UKLPG certified

Not necessarily, the installer must do a good job and UKLPG certified unfortunately doesn't guarantee that. There are good and bad there are certified and not but while most certified installers fall into the good category, some don't and vice versa. Granted and that's partly the reason why I'm poking around this forum. But, UKLPG is a must for me anyway because of insurance at least

The equipment must hold up to a certain standard (not all UKLPG installers use such equipment)

It must be up to the job of supplying sufficient fuel for your car but the Pruis isn't exactly a high performance motor so just about any kit would be up to the job.I understand that but I've been told that all parts of the equipment must meet a certain safety standard (can't remember the name). So a UKLPG installer can apparently fit a perfectly well specced and working system but it can be the case that not all components meet this certain standard (kind of like the CE label for electrical equipment)

The Prius can be tricky to convert because of the 0RPM state

This is where it gets complicated. With most installs the reducer and injector performance is critical and the choice of controller is largely irrelevant, with a Pruis it is the other way round as, as you point out, the controller must be capable of allowing a restart on LPG (or at least with a minimum start to changeover time) and a lot have a minimum petrol run time of 20 seconds or similar.Yep, that's what I've heard more or less and it seems that some systems switch over quicker than others (hard to find clear answers on that one). Since so many non hybrids cars are stop-start nowadays (even the new M3 has it I think), I would think that this is not such a big issue anymore?

It seems that a Prins Silverline kit installed by an approved garage should meet all the requirements. I’ve been told to save some money and not go with VSI as the Keihin injectors were designed to work with more than just LPG systems so are more expensive.

Keihin injectors are better quality, that is why they are more expensive. But is this a case of over engineering or is that quality needed? Will other injectors cause intermittent issues, break down more often, return less MPG...?

Can anyone give further advice? Should I keep shopping around or is the above the safest bet? Should I just pick the nearest Prins installer or are some better than others?

Prins is a manufacturer approved install only so the chances of getting poor quality install is reduced. Contact Woody on here, he is a Prins installer who has experience of the more obscure installs. Will try and get in touch. I guess a recommendation on this forum means a lot

[rossko]

this a case of over engineering or is that quality needed? Will other injectors cause intermittent issues, break down more often, return less MPG...?

Those of us who fit Keihins will tell you that is the case; you are paying for the long term reliability, which is comparable to petrol injectors. Other types can need replace or refurbish at 50,000 miles.
Whether the extra investment is sensible or not depends very much on whether you realistically expect to do 150,000 miles in the vehicle. It's pointless fitting Keihins on an older car for example.

[Gilbertd]

UKLPG is a must for me anyway because of insurance at least

Any decent, non-UKLPG, installer will be able to have the system inspected by a member and get the conversion entered on the database for insurance purposes. Even a DIY installation can still be checked by a member and certified.

I've been told that all parts of the equipment must meet a certain safety standard (can't remember the name). So a UKLPG installer can apparently fit a perfectly well specced and working system but it can be the case that not all components meet this certain standard (kind of like the CE label for electrical equipment)

Unless someone is going to try to buy parts from a hardware shop, then all of the components will meet the standard (ECE Regulation 67.01) and will be marked to say that they do. This even includes things like hoses and pipework. There is the Code of Practice for installations that every installer will have to meet for the install to be certified.

Yep, that's what I've heard more or less and it seems that some systems switch over quicker than others (hard to find clear answers on that one). Since so many non hybrids cars are stop-start nowadays (even the new M3 has it I think), I would think that this is not such a big issue anymore?

When the engine is cold all systems will start on petrol until it is up to a preset temperature when they change over to gas. Once up to working temperature they will usually start on petrol and then switch over after a preset delay, this varies between different controller manufacturers and can be anything up to 30 seconds which would be no good to you. I know there is at least one system that can be set with 0 seconds delay so will restart on LPG but can't remember which one it is (but there was a lot of head scratching over a previous install on a Prius). LPG technology is always going to lag behind conventional car technology as the manufacturers don't know what the car designers are going to come up with until it happens. Personally I think stop-start is a particularly stupid idea. What little you may save in fuel costs you'll end up spending on replacement starter motors and batteries. Assuming the rest of the car lasts that long! But, as I was told by someone in the business a couple of weeks ago, cars are becoming white goods, they aren't being built to last these days and the manufacturers don't anticipate them being around for more than 10 years or so. What concerned me most was that this was from someone at Tata, who now own Land Rover, and up until now 75% of all Land Rovers ever made are still on the road.

But is this a case of over engineering or is that quality needed? Will other injectors cause intermittent issues, break down more often, return less MPG...?

Not so much over engineering as quality. A set of Keihin injectors will probably outlast the car, whereas something like cheapo Valteks have been known to be worn out after 40,000 miles. It's like anything else these days, you can spend more money and buy a Sony TV that will last for years or you can spend a lot less and get Chinese made supermarket own brand. They'll both do the same job but one will do it for a lot longer.

[billynoband]

You don't need an expensive system to run the Prius and mid-range kits are very good quality usually. You need one that will switch straight to lpg during re-start after the engine cuts off in stationary traffic or you will use too much petrol.
Someone on Priuschat fitted a Stag system themselves with success although I don't know if it does the abouve. One member on here had a e-gas kit fitted and had good running from it.
Talk to Classicswede for a quality mid-range kit or Woody if you want top of the range Prins. Both frequent here.
Good luck and please let us know how you get on long term.

[classicswede]

Thanks for the referance

I was involved in the very first conversion of a Prius and have done many since. Self fit is an option but the latest variant is a lot harder to do with space limitations.

They will work well with either a mid range or primium kit but the system does need to be capable of restarting on gas with a warm engine due to the engine cutting in and out.

[LPGTECH]

hi one of my customer has fitted LPGtech in to Prius. all working well, when car going to electric and rpm signal gone lpg system switching off. when revolution comes back it starts straight away on gas and drive away. if you want to contact, ECO LPG in Peterborough for reference

[Gilbertd]

That's a new one. I've lived in Peterborough all my life and know most people involved in cars in one way or another and have never heard of them. In fact, when I got my first LPG car, there was only one LPG installer in Peterborough and it wasn't them. I'll have to go and have a nose around......

In my opinion the only sensible conversion to a Prius would be to throw away all those batteries, the electric motor and the little petrol engine that lives in there and fit a Lexus V8 instead!

[autofrt]

DIY Prius conversion kits were also sold on ebay. Not sure if they are any good.

[billynoband]

That was Classicswede selling them so they will be good.

[semo.pz]

Thanks for the referance

I was involved in the very first conversion of a Prius and have done many since. Self fit is an option but the latest variant is a lot harder to do with space limitations.

They will work well with either a mid range or primium kit but the system does need to be capable of restarting on gas with a warm engine due to the engine cutting in and out.

Thanks for all the feedback guys. I'm still a few months away before I jump in but hopefully I'll have all the info I need by then. Peterborough is a bit far for me (if something was to wrong for example).

classicswede, are you allowed to speak about prices on this forum? Could you give me a ballpark for high end and mid-range systems? What would I be compromising with a mid-range system? Are there any things to look out for regardless of which system I go for (for example, I know I'll have to do a yearly check in any case so are there any other gotchas)?

One more I'm wondering about and that's CNG. I know it's pretty impractical, but if anyone thinks that's not the case, let me know. I don't mind paying a little over the odds and be happy in the knowledge that OPEC sees no profit from my motoring

[classicswede]

I've sent you a message with details etc.
Prices are on my web site and there is no ectra charge for Hybrids.

[autofrt]

Would be very interested to know if the LPG conversion was carried out and also the results?