are so many options when it comes to 4x4 engine modifications. Some will
increase power, some will improve the vehicle's fuel economy and other
modifications do both.
Diesel Engine vs. Petrol
It all comes down to what type of driving and requirements you have of the vehicle.
Diesel 4x4 Engines:
The diesel engine is the most common 4 wheel drive; the
reason for this is that 4WDs are used widely by farmers in Australia and in some
remote areas there is no petrol available.
What a diesel powered vehicle lacks
in acceleration/take off speed and power, it makes up for in range and torque.
For towing diesels are better.
Diesel burns slower than petrol and this is why
it generates more torque at lower rpm.
See Eric McGrew's interesting write up about old diesel motors HERE.
Driving with a Diesel 4x4 powered vehicle:
A diesel 4x4 has an advantage when it comes to hill climbs, hill descents, rock crawling and anything that requires low speed.
This is because the engine can idle at lower rpm than the petrol engine. Some of the newer diesel 4x4’s are nearly impossible to stall.
The petrol engine is an option in most 4 wheel drive make
and models. Petrol is available in most areas with the exception of farms,
working stations and some very remote areas.
Petrol powered 4WD’s tend to
drink more fuel than the diesel; this is mainly because petrol burns faster
than diesel. A faster burning fuel allows the vehicle to gain more power and
accelerate to high speeds way quicker than the diesel.
A petrol engine size of 3.6l V6 or higher
will tow anything with no problems but it does have a poorer fuel economy
compared to a diesel.
4 Wheel Driving with Petrol
Off road a petrol engine has an advantage when it comes to sand
tracks, beaches, sand dunes and mud runs. The reason for that is acceleration,
sand driving is a combination of speed and momentum and mud is all about
spinning those mud terrain tyres in order to flick the mud from the tread blocks.
What the petrol engine does lack however is the low end torque so stalling is
common, if driven correctly this is no real problem.
If driving an older petrol engine
(carburetor engine) take good care not to stall on steep hills as the engine
will not be able to receive fuel from the carburetor due to gravity working
against the flow.
The links below go into more detail on engine modifications for Diesel 4x4 and Petrol 4 wheel drives:
Diesel 4x4 Engine modifications:
Exhaust Systems, Turbo chargers & LPG injection to Diesel.
Petrol Engines modifications:
Performance chips, Exhaust Systems, Super chargers & Sprint Booster.
Snorkels and air intake filters:
Snorkels & Air filter.