Corolla E12 1.4 D4D Fuel Economy Improvement

[angryengineer]

Dear Form 🙂,

I made some minor changes to my 2005 Toyota Corolla 1.4 D4D saloon that has resulted in pretty substantial fuel economy/mileage improvement.

I thought I would share the details here should they be of interest to anyone with the same vehicle.

Before I write anything else, please know that I am EXTREMELY SKEPTICAL of oil or fuel additives. My past experience is that they are worse than useless.

The car engine has 255,000 km run up on it.

My plan was to make minor changes/improvements in my effort to see how long I can make this car last and discern for myself if the Toyota reputation for longevity is real.

The following changes resulted in a consistent 46% improvement in fuel economy from my car when driven on short city journeys:

(1) I added a 2% v/v Liqui Moly molybdenum disulphide pro-line gear oil additive to a 98% v/v Liqui Moly fully synthetic 5w30 API-GL5 gear oil.

(2) I added 240 ml Liqui Moly molybdenum disulphide pro-line engine oil additive to 4.56 litres of Comma 5w30 fully synthetic engine oil (a 5% v/v mixture of the molybdenum disulphide additive to the engine oil)

(3) I added 36.7 ml of Hydra Diesel Power Blast to 54.9633 L diesel fuel when filling up the fuel tank (a 1:1500 dilution).

RESULT: an average fuel economy of 9.5 miles per litre of diesel fuel consumed compared to a prior 6.5 miles per litre of diesel fuel consumed. This is s 46% improvement.

[Devon Aygo]

6 hours ago, angryengineer said:

Dear Form 🙂,

I made some minor changes to my 2005 Toyota Corolla 1.4 D4D saloon that has resulted in pretty substantial fuel economy/mileage improvement.

I thought I would share the details here should they be of interest to anyone with the same vehicle.

Before I write anything else, please know that I am EXTREMELY SKEPTICAL of oil or fuel additives. My past experience is that they are worse than useless.

The car engine has 255,000 km run up on it.

My plan was to make minor changes/improvements in my effort to see how long I can make this car last and discern for myself if the Toyota reputation for longevity is real.

The following changes resulted in a consistent 46% improvement in fuel economy from my car when driven on short city journeys:

(1) I added a 2% v/v Liqui Moly molybdenum disulphide pro-line gear oil additive to a 98% v/v Liqui Moly fully synthetic 5w30 API-GL5 gear oil.

(2) I added 240 ml Liqui Moly molybdenum disulphide pro-line engine oil additive to 4.56 litres of Comma 5w30 fully synthetic engine oil (a 5% v/v mixture of the molybdenum disulphide additive to the engine oil)

(3) I added 36.7 ml of Hydra Diesel Power Blast to 54.9633 L diesel fuel when filling up the fuel tank (a 1:1500 dilution).

RESULT: an average fuel economy of 9.5 miles per litre of diesel fuel consumed compared to a prior 6.5 miles per litre of diesel fuel consumed. This is s 46% improvement.

Nice results, gear oil wouldn't be 5w30 ? should be 75w90

[oldcodger]

Interesting, though would like to see what the mpg is based on a couple  of tanks full  of fuel.

What made you suddenly go all out for a Liquid Moly treatment, do you think it would deliver such result with Petrol ?

[angryengineer]

5 hours ago, Devon Aygo said:

Nice results, gear oil wouldn't be 5w30 ? should be 75w90

Correct. I should have stated 75w-90 🙂.

[angryengineer]

3 hours ago, oldcodger said:

Interesting, though would like to see what the mpg is based on a couple  of tanks full  of fuel.

What made you suddenly go all out for a Liquid Moly treatment, do you think it would deliver such result with Petrol ?

The results are based on three 55 L tanks of diesel.

I used Liqui Moly because I had read about their reputation. Also, molybdenum disulphide has been used as a solid lubricant for more than 60 years, I think, so I guessed it wouldn't damage any internals.

[angryengineer]

My most recent tank of diesel delivered 10.51 miles per litre. About 50% of the driving was at 130 kph on motorways, the remaining being short city journeys.

I really hope this keeps up! Major improvement in fuel economy 🤑🤠

[angryengineer]

On 7/8/2020 at 9:16 PM, oldcodger said:

Interesting, though would like to see what the mpg is based on a couple  of tanks full  of fuel.

What made you suddenly go all out for a Liquid Moly treatment, do you think it would deliver such result with Petrol ?

Hi oldcodger,

The Liqui Moly molybdenum disulphide (MoS2) lubrication additive for gearbox and engine should work equally well in a petrol engine. The idea is to reduce internal friction so less work is expended in rotating the gear shafts and engine internals. The work saved is expended in powering the car forward.

I found my car became quieter and had lower harshness on idle. I don't believe this to be a "placebo effect". The gearbox MoS2 additive substantially changed the operation of the gearbox. Previously, I had sensed the gearbox gear change to be slightly stiff. Addition of the 2% MoS2 really softened the gear change. It's buttery smooth and soft now. Really, it has to be experienced to be believed. Brilliant stuff

Also, on cold startup, lubrication is greatly enhanced as the MoS2 forms an adherent layer on the metal surface at all times. In fact, I have read of instances where the MoS2 additive alone was sufficient to save the internals of a gearbox even while running dry without oil.

My caution would to ensure that the molybdenum disulphide is compatible with your car's catalytic converter - inevitably, some of it will be consumed during fuel burn in the cylinders and the products will pass through the catalytic converter. It should state clearly on the container if it has been tested to be safe to use in petrol cars.