CRD Performance (Bolton) – The LPG conversion experts

CRD Performance have been carrying out LPG (Autogas) conversions since January 2000 and in this time period (to November 2012) have converted in excess of a thousand petrol engine vehicles.

Eddie's LPG Mitsubishi Evo X

Eddie’s LPG Mitsubishi Evo X

As one of the LPG industry’s few installers to originate from a specialist fuel injection background, CRD Performance are well known and respected in the motor trade as leading LPG installers and Factory fitted LPG System trouble-shooters.

Most LPG installers tend to use one or two preferred makes of LPG system and will often fit these to every make and model of vehicle that comes into their workshop in the belief that they will always achieve good results. Most installers don’t like change and are sometimes only too quick to criticise other systems, often labelling them cheap or just rubbish, especially those systems originating from Eastern Europe.

Comparing Systems

Transit Rolling Road Development As fuel injection specialists, with lots of diagnostic test equipment at our disposal and also an involvement in research and development for LPG/CNG Diesel blend systems, we make it our business to properly evaluate all makes of kit.

The majority of LPG kits are manufactured in Holland, Italy and Poland. There are others, mainly from Eastern Europe, but these are only a minority. Some companies manufacture complete front-end kits (these are the bits that fit in the engine bay) while some manufacture only the electronic parts and then outsource the LPG injectors and LPG reducers. Likewise, some manufacture the LPG injectors and reducers but then outsource the electronic components.

Italian LPG Systems

Italian Flag Take for example Bi-Gas, OMVL, Romano and Zavoli; these are all Italian companies who all manufacture their own LPG injectors and reducers but then outsource (and re-badge) the same electronic control units (ECU) from another Italian company, AEB. Ironically, the largest LPG equipment manufacturing company in the world, Landi Renzo, who are also Italian, not only buy their electronics from AEB also, but they own them too!

Dutch LPG Systems

Dutch Flag As for the Dutch sytems; Prins build their own electronics and reducers but buy their injectors from Keihin in Japan. They then claim their kits are the best in the world, all because of the good quality Japanese Keihin injectors they use. Tartarini make their own reducers and injectors but then buy their electronics from AEB, Lovato do similar but also buy their reducers from Landi Renzo. AG and Necam / Koltec are better known as suppliers of factory fitted LPG systems; they manufacture most of their own components but then also supply them to be used by Pharos and XLR8 for their LPG and CNG kits.

Polish LPG Systems

Poliah Flag Poland has several LPG manufacturing companies who export their products globally; the main three being Stag, KME and LPG Tech, all of whose kits we have used and with excellent long term results. The Poles tend to manufacture their own electronic control units and sometimes their own LPG injectors and reducers but then make their software compatible with a wide range of different injector and reducer makes. KME make their own excellent reducer while the Majic injectors they promote are probably one of the highest flowing and most powerful injectors we have ever tested using our rolling road dyno.

Polish LPGTech System fitted to a Jeep SRT8

Polish LPGTech System fitted to a Jeep SRT8

The injectors are without doubt the most crucial component in any LPG system and apart from Keihin in Japan (Prins), the Korean made Hanna and Polish Barracuda injectors, that we often fit, are probably the best available.

One of the few companies we believe manufacture and sell only their own equipment is BRC in Italy. We still rate this as probably the best make of kit available all round, but expensive when compared to the Polish kits.

There definitely are some “rubbish” kits on the market, but just because kits or parts come from countries where manufacturing costs are lower, it shouldn’t be thought said they are all rubbish – far from it!

Sadly, due to the lower purchase cost of some of the Eastern European LPG kits, they can attract less competent installers who, for very little cost, will fit a full LPG system in a day (a day!). To correctly install an LPG system takes a competent UKLPG qualified Fitter between 2 and 4 days, depending on the engine cylinder configuration and tank type used.

Following installation, the LPG system has to be programmed, calibrated, and then the vehicle road-tested using a Scan tool, to ensure correct fuel trim set up. Installations carried out in one day can’t possibly allow for any quality control or margin for error. We’ve known some of these one-day installation companies to even supply their customers with a plug-in calibration lead and software, encouraging them to attempt to rectify any poor running concerns themselves.

CRD Performance often use their Sun Ram X11 Rolling Road Dyno to set up newly converted vehicles, especially where the customer has requested that performance on LPG should come before economy. Some petrol vehicles leave the factory running so lean on wide open throttle that just by adding a little more gas on acceleration can improve BHP and torque significantly.

Dyno Setup and Checking of a Newly Converted Vauxhall Astra
Choosing the right LPG System

When choosing an LPG kit for a specific vehicle application, we at CRD Performance have several things to consider, including first and foremost the customers budget.

Other things we need to consider are what the vehicle’s main use will be. For example; is it going to be used as a Taxi or Learner Driving School car? Will it be continually stalled or stop-started and therefore be requiring a specific type of LPG system that allows instant gas start up when the engine is warm.

Is the owner interested purely in fuel savings or is he/she a ‘petrol head’ looking for an increase in performance too. Does the engine rev at a very high RPM, requiring special high-flow injectors and will it require additional valve care lubrication? Is the engine supercharged or turbocharged and therefore requiring the LPG reducers to be installed using MAP sensors and boost compensation?

How long the vehicle is likely to be kept? will the owner wish to remove and refit the same system to his next vehicle? Is the engine intake manifold easy to adapt for LPG injection or are long pipe lengths necessary therefore requiring an abnormally high gas pressure and use of high current, low impedance injectors? Is it a high powered vehicle and will it require two reducers? Will it also need a fuel return modification because it has a return-less fuel system?

And so the list goes on, and on …

So now you might appreciate how difficult our job is to provide you with the results most of you demand or take for granted.

If you are serious about having your vehicle converted to run on dual fuel and have read about us at CRD Performance then please call us to discuss any further concerns or issues you may have. The price we quote might be more than some other installers; that’s not because we’re dearer, it’s because we charge for the time we spend, to give you the finished results that we are so proud of and are so well illustrated on this website.

Which LPG System do CRD Performance Recommend?

STAG LogoCRD Performance have been installing most makes of LPG systems for over 15 years now and honestly believe that considering the development work we’ve been involved in and number of different kit makes we’ve tested, some good, some not so good, then our opinion on choosing the best make of system currently available should carry some credibility.

Most LPG installers tend to try several makes and then, for whatever their reasons choose one make they feel comfortable with, this may be due to the complexity of that kit and their technical ability. They then try to convince every potential customer, on every new enquiry, that their chosen make is the best one to have no matter what their vehicle.

Honda Hybrid Electric STAG LPG conversion

Honda CR-Z SP I-VTEC IMA Hybrid Electric STAG LPG conversion

CRD Performance, as recognized fuel injection specialists for both petrol and diesel blend LPG and CNG, have their own in house rolling road dyno testing facility and are actively involved in LPG Diesel Blend development. Directly as a result of this development work we have been fortunate in being able to install, test and evaluate not just most manufacturers complete LPG systems but also most, if not all, the many different makes of the so critically important LPG injectors and LPG reducers.

Some branded LPG kit manufacturers (eg.Prins, BRC, Zavoli.) will only sell their systems to installers as a package, complete with their own brand of injectors and reducers as part of a front end kit.

We believe a better approach is to compare an LPG system to an Audio Sound System where different makes of separates make up the best reliability and sound quality. Sony for example may build the best amplifier, Technics the best Tuner and Mission by far the best speakers. Using this example Prins may build the best ECU but the best injectors might be the ones BRC build but the most reliable and highest power reducer could be manufactured by Zavoli.

Honda CR-Z SP I-VTEC IMA Hybrid Electric STAG LPG conversion

Honda CR-Z SP I-VTEC IMA Hybrid Electric STAG LPG conversion

At the time of originally compiling this website about 3 years ago, we would have strongly favoured the BRC system as being our number one choice, closely followed by Prins and then Zavoli. Whilst in recent years the Italian and Dutch LPG manufacturers seem to have stood in developing their systems (excluding of course any recent direct injection systems) the Poles have made massive steps into making their systems the best performing, most reliable and technically the most advanced in the world.

If we had to choose today, just one make of LPG system, based on reliability, cost, suitability, performance, driveability and value for money (for ALL non direct injection types of vehicles) the unanimous choice from all at CRD Performance would without any doubt whatsoever be the AC. Stag system.

CRD Performance first used the AC. Stag brand during development of their LPG/CNG Diesel Blend system and it impressed us so much that we’ve made it our No.1 preferred choice for all current petrol to LPG conversions. This kit is awesome; it allows us to do things we’ve always wished for but not been able to do before.

Honda CR-Z SP I-VTEC IMA Hybrid Electric STAG LPG conversion

Honda CR-Z SP I-VTEC IMA Hybrid Electric STAG LPG conversion

What helps even more, and gives us yet a further advantage over most other LPG installers is that Eddie Zyla, the owner of CRD Performance, was born in England to Polish parents but speaks both fluent English and Polish. Needless to say, with there being no language barrier we have no problem at all when needing technical assistance or to discuss any special software requirements.

Unlike some LPG system manufacturers, AC. Stag have produced their own ECU (electronic control unit) but then programmed it so it can be used with almost any make of LPG injectors or reducer type currently available. Stag also manufacture in house their own design LPG injectors and LPG reducer as well as complete wiring harnesses, pressure sensors, connectors, looms and switches, in fact just about any part required for an LPG system.

Honda Civic Type-R STAG LPG conversion

Honda Civic Type-R STAG LPG conversion

This new approach from Stag allows LPG installers to tailor make a full kit for their customers particular requirements based on vehicle type, available budget, life expectancy, reliability, performance requirement, installation quality, appearance and driveability.

By choosing cheaper components with a shorter life expectancy and fitting them quickly in the easiest and non-cosmetically pleasing way, overall vehicle performance and driveability may be compromised but the customer will get a quick and cheap installation.

Alternatively, the same Stag ECU control system can be installed by CRD Performance but using the best available and most suitable make injectors and reducer(s) to suit the performance requirement of the vehicle. The vehicle is road tested and diagnostically checked using a scan tool before installation and the customer advised of any current fault codes present or driveability concerns, if required, these could be properly diagnosed and rectified, at an additional cost of course.

Honda Civic Type-R STAG LPG conversion

Honda Civic Type-R STAG LPG conversion

The LPG injectors will be installed using correct size jets and manifold nozzles to ensure faultless driveability and performance, these will be installed in a cosmetically pleasing way ensuring all wiring is shortened where necessary and neatly loomed using black cloth tape. Final set up and calibration is carried out by a skilled fuel injection engineer using our rolling road where necessary to ensure the best possible performance is achieved followed by further on the road map refinement ensuring optimum driveability and performance.

The Stag AC LPG System has some unique features not present in most of its competitors systems and it’s our opinion that many of these are as a result of the Stag software engineering team’s reaction to their installer’s requests. No matter how perfectly designed an LPG system may seem to its makers the real test is when installers fit them to many makes of vehicles, all with different performance and driving style requirements.

Honda Civic Type-R STAG LPG conversion

Honda Civic Type-R STAG LPG conversion

It’s the advanced driveability features and proven reliability of the AC.Stag system that make it in our opinion the best LPG/CNG system currently available anywhere in the world. Without going into too much detail of all the Stag systems features we can summarise and say that whatever the engine capacity, number of cylinders, BHP or engine type, the Stag system is able to cope with it. No matter how awkward or difficult it proves to “Gas”, Stag can deal with it, be it naturally aspirated, (standard), Turbo Charged, Supercharged, Valvetronic or even a Wankel engine, the same Stag ECU fits all.

Recent software additions have included fuelling corrections using can-bus data from the vehicle’s OBD port and even automatic cancellation of specific OBD fault codes caused by the slight differences in combustion properties between petrol and LPG. Vehicles which normally require an additional Flashlube system to lubricate valves can now use Stag’s unique new petrol split fuelling option to further help minimise the risk of valve seat recession.

Unfortunately, due to the weak currency exchange rate between Poland and Western Europe, these kits are cheaper to buy in the UK than most of the kits manufactured in Holland or Italy and therefore very popular and often used by low cost budget non LPGA certified back street LPG installers. The Stag product range is huge but unfortunately, in an attempt to keep installation costs to a minimum, some installers still cut corners and often use the incorrect and cheaper readily available interchangeable parts for some installations.

AC. Stag permanently employs about 500 staff in Bialystok Poland and in peak demand times this often increases to about 850. Stag are by far Poland’s No1 LPG/CNG equipment manufacturer supplying over 75% of the domestic market. There are other well known Polish LPG system manufacturers whose names include LPG Tech, KME and Europe gas, to name just a few, these are also recognized as being very good and still technically miles ahead of, for example, BRC, Prins, Zavoli, OMVL, Romano, Bi Gas, Landi Renzo, stefanelli, Lovato, Necam and Koltec and Ecotech etc.

Honda CR-Z SP I-VTEC IMA Hybrid Electric LPG conversion on the rolling road.
Honda Civic Type-R GT I-VTEC LPG conversion on the rolling road.

What we are trying to say here is no matter what you’ve heard either on the forums or from a man in a pub about how good or bad Stag LPG systems really are, take no notice of them and make up your own minds after reading this.If you are serious about getting your vehicle converted, be it from petrol to LPG or diesel to LPG Diesel Blend, (and are in agreement with our prices) then make an appointment to come and see us. One of us will take you out in either the high performance Mitsubishi Evo X LPG (petrol) or Mitsubishi L200 LPG (diesel blend) and demonstrate to you the Stag LPG system in action after which we will be happy to answer any technical questions you may have.

Budget Systems
Hanna Injectors

Hanna Injectors (on a V6 Jag)

Whilst CRD Performance specialise in fitting LPG conversions to a very high standard, similar to those you would expect to see on factory fitted systems, we are often asked if we can provide budget installations.

We are aware that vehicle owners looking to convert their vehicles want the conversion to be carried out to a safe and professional standard but some can’t quite afford the higher costs this can incur. For this reason we have decided to introduce a lower cost budget installation option as an alternative to our standard high quality installations. These budget installations are carried out to the same high-standards but the cost (labour) savings are made where cosmetics are concerned, focusing on an installation that is more functional than aesthetically pleasing.

To reduce cost, all brackets are usually manufactured using galvanised steel so that they don’t require painting. Any pipe-work and components are fitted in the least time consuming way possible, avoiding any unnecessary removal and refitting of panels and vehicle trim. The electrics are installed using much quicker methods too, retaining the standard wiring insulation that is supplied with the LPG system kits, while again avoiding the removing of vehicle trim. To keep costs to a minimum only single hole (rather than 4-hole) tanks are used. The LPG filler doesn’t include a body-colour paint match option and it will be mounted in the simplest and most convenient position. The LPG changeover switch, which is fitted inside the vehicle, will also be mounted in a location that makes installation quick and straight-forward, often using a bracket to save removing part of the dashboard or centre console.

All budget installs are carried out by the same highly trained staff with all the same preparatory checks, including a road test and checking the vehicles on-board diagnostic system (OBD) for any fault codes using a scan tool.

Initial set up of the newly installed system is carried out using the appropriate software and a standard calibration is performed (like most installers do) in accordance with the kit manufacturer’s instructions. To keep costs to a minimum a set up using our Sun Ram X11 rolling road or wideband lambda sensor air to fuel ratio monitor (for 4WD Vehicles) is not included.

Budget Installation Costs

We are limited how many low-budget installations we are able to carry out at any given time and of course our standard, high quality LPG installations have to take priority. Why not call us to discuss your requirements and your budget. It may be that we have available an ex-demo kit that we’ve trialled or even a low mileage kit that we’ve taken off one of our own LPG Diesel-blend development vehicles. We’ll even sometimes have brand new kits available at reduced prices that have previously been installed on customer’s vehicles and then removed, unused, to be replaced with a more suitable upgraded kit.

Manager, Vinny - Keeping his hair on

Manager, Vinny – Keeping his hair on

Any budget kit we supply and fit, used or new, will still be covered by the minimum 12 months or 12,000 miles warranty. Please call us: Speak to either Eddie or Vinny and feel free to haggle as much as you want – We want your business!

All we ask of you when leaving your vehicle for a low cost budget conversion is please be patient. The installation may take one or two days longer than normal. We will do everything to turn around your vehicle as quickly as possible, but remember – full paying customers come first.

Installation Costs

LPG conversion costs vary greatly due to 3 main governing factors: One factor is the number of cylinders the engine has. The cubic capacity (cc) is of less importance because large LPG injectors cost the same as small ones. For very high power engines it may be necessary to install 2 reducers or at least one high power type unit. LPG kits are available in 4, 6 and 8 cylinder configurations. 3 and 5 cylinder engines generally use 4 and 6 cylinder kits, respectively. V10 and V12 engines are usually converted by using two standard 6 cylinder kits.

Under-slung toroidal installation being carried out.


Similar SRT-8 with a cylinder tank installation with optional MDF fabrication and trim work.

The second factor depends on which type of LPG tank is required, e.g. a lower cost single hole tank or the more expensive 4 hole type. Also, if the vehicle is high-powered, a high flow-rate tank multi-valve may also be required. Toroidal tanks mounted in the vehicle’s spare wheel well are relatively quick and easy to install. By comparison, under-body toroidal tanks often involve time consuming fabrication of a custom frame and mounting brackets. Boot mounted cylinder tanks are also time consuming to fit correctly since mounting them usually requires a cradle or frame that has to be securely fastened to the vehicles structure.

Manifold Straws

Installing Manifold Straws

The third factor is how complex the front-end installation is, how long it takes to fit the kit securely and neatly into the engine bay and also whether a ‘valve care’ or fuel return system is required.

We also have to take into account whether the inlet manifold must be removed and whether additional extra long LPG ‘straws’ or gas nozzles need to be installed.

Price Guide
A 4 Cylinder LPG system fitted to an average power, standard family Saloon, Coupe or small van, using a single hole toroidal LPG tank. From £1300 + VAT
6 Cylinder LPG system (as above) From £1500 + VAT
8 Cylinder LPG system (as above) From £1600 + VAT

For higher powered vehicles (including Turbocharged and Supercharged) requiring high-power injectors, different reducer(s) or a 4-hole toroidal or cylinder LPG tank, allow for an additional £200.00 to £400.00 +VAT.

For 4X4 Vehicles fitted with V6 and V8 high-power engines, requiring large boot mounted cylinder tanks or 4-hole under-body tanks (which often require high-power LPG injectors and high-power single or twin reducers) prices start from £1800.00 + vat.


Below are some prices and examples of vehicles we have recently converted.

List coming soon …

Vehicle Manufacturers Some vehicle manufacturers offer LPG conversions as a factory-fit option. Such systems are invariably manufactured by well-known gas conversion kit manufacturers rather than the manufacturer of the vehicle on which they are installed.

We regularly service, repair and upgrade factory fit systems and have a vast amount of experience and equipment for use when working with these systems.

Factory Fit Systems Cross-reference Information

Below is a list of some popular factory fitted systems and Powershift systems,  and the vehicles that you would likely find them on

Necam / Koltec Vauxhall
Metatron / Icon LDV
Vialle Nissan
Pharos Mitsubishi
EuroGas & AG Citroen
Landi Renzo Landrover

Necam-Koltec Reducer

Necam/Koltec Reducer

Fuel Filter

Fuel Filter

Fuel Distributor

Fuel Distributor


After-Market Kits

We also specialise in after market systems and we able to repair and service all makes.

Range Rover Injectors

KME G3 LPG Injectors shown fitted to a Range Rover 4.4

Below are just some of the systems we frequently repair or work with.

Multipoint and sequential injection kit manufacturers

BRC Sequent
Sequent Fast
Sequent 24
Sequent 56
Sequent Plug and Drive
Sequent Direct
Just Heavy
Zavoli Alesei
Romano RIS
Prins VSi
OMVL Dream
BiGas Sgis
Tartarini ETAGas
Landi Renzo Landi Omegas
RSI plus
Lon Gas
E Gas
Icon JTG
Motor Gas
Motor GPL
Star Gas
Voltran Vogas


Single point Manufacturers

Prins YPS
BRC Just
Zavoli Regal
OMVL Millenium
BiGas Pegaso
AEB Leonardo
Tartarini TEC97/98/99
LX 1


Tank Manufacturers

Most front end kit manufacturers do not make their own tanks.

The most common tank and valve manufacturers are:

Tugra Makini