2012 year analysis

The first full year and a driven distance of 16800km, the only relevant expense this year with the Corolla was the lpg system fitted in early July, making it the daily driver since then (it was used every other week).

This year's costs.

Scheduled maintenance: 94,91€

Periodic compulsory inspection: 28,18€

Road Tax: 54,06€

Insurance: 160,84€

Spare parts: 9,00€

Tires and steering alignment: 192,00€

Cleaning products: 24,85€

LPG system installation: 2337,00€

Fuel: 1338,45€ (which 649,45€ in petrol)

Total: 4239,29€ (0,25€/km)

Everything seems to go just about fine, estimated total distance to break even is 50646km... 38805km to go!

Valve clearance check... take 2

Once again, after 11500km on LPG, I decided it was time to check on the valve clearance. This time the engine was cold, so the measurements should be more accurate than last time.

After removing the engine cables, the coils, the spark plugs, the valve cover breather and, finally, the valve cover, I could take a reading on those clearances... these were the values measured:

Intake valves: 0.25mm

Exhaust valves: 0.35mm

Since the problem is the reduced clearance... I'd say I have a pretty good chance of getting away with it.

The second pair of tires

A new pair of tires was needed, the remaining pair of Bridgestone's in the front axle (I always fit the new tires on the rear) were worn almost to the limiters, so a new pair of Yokohama's C.drive 2 were bought to fit the rear axle, leaving the older ones the job of steering the front end.

In place they costed me 192€, including steering alignment. The Bridgestone ran for about 32 thousand kilometres.

After a short run, the already used Yokohama's seem far better then the Bridgestone's, although this just might be a natural consequence of reaching the final life span of the Bridgestone's.

Servicing again

At 460km/week after the LPG installation, it got to the service distance quicker.

This time rear brake discs and pads were fitted adding to the oil change (5W30, Toyota recommendation for the 3ZZ engine), oil filter and clutch/brake fluid. Also there was a annoying squick when pressing the clutch pedal, this was due to dirt and lack of lubrication on the clutch actuator (it seems to be something usual in this cars), after cleaning and lubricating with cooper grease... silence again.

Service distance 137237km (8878km on LPG), service cost was 94.91€.

Still not switching

After readjusting the tank level by means of software update the system still doesn't switch form LPG to petrol when the LPG tank goes dry... let us wait a little more for a definite solution to this.

At this point, a little over 5000km running on LPG, the commuting expense dropped 46.8%, still need something like 38750km to break-even.

Valve clearance check

Since the Toyota VVT-i engines are prone in valve seat recession when running on LPG, I decided to take a reading of the valve clearance (even after being told that this would not be a problem by the guys at Front Fuels).
This is the valve clearance readings that I got:

Intake valves: 0.15-0.25mm, reading was 0.20mm
Exhaust valves: 0.25-0.35mm, reading was 0.30mm

The engine had been stopped for some time but it was not "completely" cold, so the values could be somewhat bigger than expect at cold engine temperatures.

This reading was taken at 131357km (2500km on LPG)

Service of the LPG system

The only service required to a liquid injection system is made after the 1500km mark.

This service consists in various leakage checks and the correct functioning of the LPG ECU and fuel tank pump.
Since nothing was deemed wrong, the Corolla got up and running with only one single remark. It doesn't automatically switch to petrol when the LPG thank goes dry.

This should be solved with a ECU software update from Vialle itself... so we wait.

LPG liquid injection

After some setbacks on the installation and 2337€ worth of hardware, the Corolla returned home with the LPG system installed at Front Fuels

It is a Vialle LPi liquid injection system, with a 47 litre tank (fills up with approximately 39 litres, due to safety measures) and it should avoid the valve seat recession by itself (it injects petrol while running on lpg to do so)... and here the LPG experiment truly begins at the 128359km mark!