W211 E55 LPG Conversion

[Gib]

Greetings folks. I've signed up to the forum to research one of the cars on my shortlist. I currently run a 2000 Mitsubishi Galant VR4 with an LPG conversion.

Looking at 2004 E55 AMG to replace it next year, just wondering if anyone is running one with a LPG conversion? My Mitsubishi is a mere 2.5 litre V6 with a pair of small turbos and it's running around 300bhp with no issues on LPG. I've grown used to paying 50p a litre for gas instead of 127p a litre for V Power.

My installer tells me that the M113K can be converted, just wanting to get some input from anyone who has already had it done. The W211 looks like a cracking buy for the money, £10k for a well specced superbarge is good in my book. I know they will still have high running costs but the initial outlay is reasonable.

 

[John]

Welcome to the forum.

I maybe wrong but I don't think we have any LPG-converted E55Ks on here before.

I remember the odd question about it in the past though.

 

[kopkid]

???? You buy it for what it is ,,a beast!!!

 

[Gib]

Welcome to the forum.

I maybe wrong but I don't think we have any LPG-converted E55Ks on here before.

I remember the odd question about it in the past though.

Thanks for the welcome. I've found a few old threads but they mainly ended up with the thread starter getting grief for considering the conversion.

???? You buy it for what it is ,,a beast!!!

I'm aware of the performance stats for the E55. I'm also mindful of the fuel costs. I ran an X308 XJR for a while and was used to 16mpg for daily driving. My Galant did 16-18mpg on V Power. Cost per mile was halved when I switched to LPG. This then leaves more money for mods and with the E55 that means fun stuff like a remap, LSD, pulley upgrade, exhaust etc.

I'm aware of the stigma with LPG that stems from poor installs and internet hearsay. I've had nothing but positives from it, my engine puts out the same power on it as it does on V Power and money saved in a year of running on LPG has already exceeded the cost of the installation.

I would be keeping the E55 for 2-3 years so in my eyes it makes sense for the conversion given that it would be used daily and that I average anywhere from 10-15k a year. Pity there is no on here who has gone down this road yet.

 

[whereami]

Gib, I own an E55 Estate (2005) that runs on LPG. I bought it three years ago from the chap who had the conversion done. According to the invoices he had the conversion done at about the 40,000 mile mark, I bought it with 99,000 on the clock and have since added over 30,000 miles myself.

So yes it is definitely doable. I have also seen a saloon for sale on Ebay that had been converted (claimed to be the only one in the UK, obviously isn't )

The car runs well on LPG, only running out of steam at over 4000 rpm at full throttle, research leads me to suspect that the kit fitted has a slightly under-spec evaporator. It should I thnk have had two fitted, although I believe newr kits are available now with larger capacity evaporators.

I have only done regular maintenance and the usual repairs associated with this model at this milage (suspension air pump, heat exchanger coolant pump etc)

Let me know if you want to know more, sorry for the late reply, I have only just seen the post.

 

[Gib]

Gib, I own an E55 Estate (2005) that runs on LPG. I bought it three years ago from the chap who had the conversion done. According to the invoices he had the conversion done at about the 40,000 mile mark, I bought it with 99,000 on the clock and have since added over 30,000 miles myself.

So yes it is definitely doable. I have also seen a saloon for sale on Ebay that had been converted (claimed to be the only one in the UK, obviously isn't )

The car runs well on LPG, only running out of steam at over 4000 rpm at full throttle, research leads me to suspect that the kit fitted has a slightly under-spec evaporator. It should I thnk have had two fitted, although I believe newr kits are available now with larger capacity evaporators.

I have only done regular maintenance and the usual repairs associated with this model at this milage (suspension air pump, heat exchanger coolant pump etc)

Let me know if you want to know more, sorry for the late reply, I have only just seen the post.

Thanks for the reply. Glad to hear that the conversion has been hassle free for so many miles. I had a few teething issues with full load launches on my Galant after the conversion where it would switch over to petrol but they were ironed out by my installer. Do you have any pictures of the tank install and any information on the make/spec of the kit? Also what sort of range do you get from the setup? Are you still running a stock engine setup or have you had a remap done?

I guess a remapped and setup E55 with LPG would be the very definition of having your caking and eating it.

 

[whereami]

No Problem. I am off to work in a few minutes (nights) so will get some photos for you tomorrow, and check what the kit make is (can't remember off the top of my head) I can say the tank is a toroidal one in the spare wheel well under the load area floor, capacity of 70 ltrs, so range is a little limited (around 190 miles of everyday driving per tank) The car is standard at the moment but my intention is to do some mods, ideally exhaust manifold, heat exchanger, smaller pulley and remap but I think with all that I would have to address the evaporator issue as well...

 

[Gib]

Brilliant, thanks. I have a 60 litre toroidal one in the Galant and get similar range from everyday driving. I only live 3 miles away from my workplace and the short commute doesn't help mpg. I'm looking at the same sort of mods as you have planned. The LPGTech kit in the Galant can handle up to 8 injectors so would be looking at the same setup in an E55. Whereabouts is your filler situated? I went for the discreet option alongside the petrol filler. It means I need to use an adapter when filling up but does negate the need for cutting into the bumper and having the cap colour coded.

 

[cazyp]

Depending on the conversion cost, the falling price of unleaded vs LPG and your proposed mileage i'd guess it's going to take you some time to recoupe the difference?

 

[Gib]

Depending on the conversion cost, the falling price of unleaded vs LPG and your proposed mileage i'd guess it's going to take you some time to recoupe the difference?

I've not got a quote from my mechanic yet but I made back the install cost on my Galant in a year from the fuel saving based on price per mile on supermarket LPG vs Shell V Power. Would be keeping the E55 for two years at the minimum and will be looking to do more miles in it than the Galant. I'm guessing E55 owners use 99rob and not 95ron?

 

[V12]

The 55k engine runs perfectly fine on 95 RON and will easily outperform a car running on lpg, simply due to the energy content deficit that lpg has.

It is an interesting thing to consider. In the short term we are expecting another couple of fuel price drops. Petrol is now under 110p per litre in some places.

 

[John]

I always use 99RON Momentum and have done since I got it in March 2011.

I wouldn't skimp on it to be honest - I once owned a car which pinked on anything less than 98RON which actually wasn't available at the time.

 

[MOR8A]

Same.......only ever used momentum 99. Call it being cautious, just made me feel more comfortable.

I always use 99RON Momentum and have done since I got it in March 2011.

I wouldn't skimp on it to be honest - I once owned a car which pinked on anything less than 98RON which actually wasn't available at the time.

 

[Gib]

I was under the impression that LPG has a higher octane rating? I've seen back to back dyno runs of my mechanic's car (estate version of my car) where he was putting out a few extra horses on LPG compared to V Power.

I wouldn't want to run an E55 on regular fuel. My Galant is an import and is mapped for 98ron minimum. I still run it on a few litres of V Power over the course of a month.

 

[V12]

High octane yes, but lower energy content.
It is typically considered that lpg cars will never produce 100% of the power that petrol can. A deficit of 10-20% is usually quoted.

I have many miles of first hand experience driving a W220 S500 with LPG which has the N/A M113 engine. The power difference was noticeable. Especially heading up some mountain roads with the car filly loaded with weight.

I'm not saying the 95 RON is ideal or the best but the M113 engines are perfectly happy on it. They are a very strong motor. 95 RON is considered premium in many countries. In the US, their 90AKI is equivalent to our 95 RON

A high octane fuel such as*Liquefied petroleum gas*(LPG) has a lower energy content than lower octane gasoline, resulting in an overall lower power output at the regular compression ratio an engine ran at on gasoline. However, with an engine*tuned*to the*use of LPG*(i.e. via higher compression ratios such as 12:1 instead of 8:1), this lower power output can be overcome. This is because higher-octane fuels allow for a higher*compression ratio*- this means less space in a cylinder on its combustion stroke, hence a higher cylinder temperature which improves efficiency according to*Carnot's theorem, along with fewer wasted hydrocarbons (therefore less pollution and wasted energy), bringing higher power levels coupled with less pollution overall because of the greater efficiency.

The main reason for the lower energy content (per litre) of LPG in comparison to gasoline is that it has a lower*density. Energy content per kilogram is higher than for gasoline (higher*hydrogen*to*carbon*ratio). The weight-density of gasoline is about 740*kg/m³ (6.175*lb/US*gal; 7.416*lb/imp*gal).

Different countries have some variation in what RON (Research Octane Number) is standard for gasoline, or petrol. In the UK, ordinary regular unleaded petrol is 91 RON (not commonly available), premium unleaded petrol is always 95 RON, and super unleaded is usually 97-98 RON. However both Shell and BP produce fuel at 102 RON for cars with hi-performance engines, and the supermarket chain*Tesco*began in 2006 to sell super unleaded petrol rated at 99 RON. In the US, octane ratings in unleaded fuels can vary between 86-87 AKI (91-92 RON) for regular, through 89-90 AKI (94-95 RON) for mid-grade (European Premium), up to 90-94 AKI (95-99 RON) for premium (European Super).

 

[DavidL]

Lower energy content so less power from lpg and also fewer mpg. My only experience is my old range rover with a 4.2 v8. Its run on lpg for the last 100k and it's fine but it does go just slightly better on petrol but it isn't ever going to be fast so it isn't really a problem! I get about 200 miles from 60 litres of lpg at around 58per litre. So around 30 mpg which for a 4.2 v8 is fine.

 

[Gib]

I've not experienced any difference in power between the two fuels, my LPG map has been set-up quite well though and the fuelling has been tweaked and I have an AFR gauge to keep an eye on things. I've done nearly 10,000 miles on LPG and I haven't held back with the go pedal.

Booked in for a dyno session in a couple of months so I will have some back to back runs and compare. My overall MPG on LPG is around 1-2 less than V Power but the cost per mile is more than half the price. I pay 49.9p per litre at the most for gas.

 

[V12]

Please don't forget to post dyno readings here when you do get it done.

We can talk theory and physics all day long but real world is what counts and I have long been very interested in the actual real world power deficit of running LPG.

 

[Gib]

I'll post the graphs here, if I'm wrong I'll happily eat my own words. Might see if I can source a timing box and do some runs to compare stats too.

 

[BFT]

Modern LPG kits that are sequential with enough 'kit' will lose minimal performance if any. Fine tuned can gain power.

Having run LPG since 2003-2012 the kits from 2007 onwards were a different kettle of fish.

Lots of crap out there. At minimum go for a BRC kit or ideally a PRINS setup.

My A8 4.2 has done 130k on LPG and rolling roaded as standard at 331bhp and on LPG 328bhp but gained 10lbs torque....!

Will dig out some info! The ECU should be recalibrated ideally as well.