Petrol and NGV quandary
Question : I BOUGHT a
used 2001 Toyota Altis 1.8G(Auto) about a year ago and it came with NVG bi-fuel
Korean system installed by the previous owner.
Mileage is about 230,000km. Upon starting in auto mode, the car accelerates
initially using petrol and changes to gas upon gear change. When out of gas, it
reverts to petrol automatically.
Since this is my first experience with an NGV car, I seek your advice on
After every 10,000km, I replace the engine oil (Toyota grade 10/40
semi-synthetic formulation ) and oil filter. After driving about 5,000km, the
level of the engine oil drops by about one-eight to one quarter of an inch of
the low and high indicator marks denoted on the dipstick (assuming the indicator
marks are about one inch apart).
when I rev the engine in petrol mode, there are no bluish white exhaust fumes
and a mechanic told me my valves are still in good condition and no grinding is
According tot he Toyota car manual, it mentioned that consumption of some
engine oil is normal especially if the car is run around for quite a distance
amidst traffic and weather conditions.
What engine oil grade is recommended for my case ?
The mechanic used a hand-held diagnostic scanner and connected it to a
pin-socket below the steering and the result was normal.
Do I have to regularly service the throttle body which is just next to the
Do the valves and tappets need to be regularly adjusted for an NGV car ?
Is the engine temperature hotter than one which runs on petrol ?
At 230,000 mileage, you can expect some oil consumption and although the valves
are in good condition, there is most probably "blow-by" past the piston rings
due to piston and ring wear, and the oil that is being burnt is going out the
You may not notice it as the volume is very small but over 5,000km, you would
notice ti in the dipstick.
Personally, I do not think you need to change the grade of oil you are using
but the valves/tappet adjustment should be done at the intervals recommended in
your service handbook.
It does not matter what fuel you are using -- maintenance services should
continue as recommended.
Regarding engine temperature, gas powered engines tend to run slightly hotter
but that is not usually a problem.