The Philippine Diesel Engine Experience

The Philippine Diesel Engine Experience image

Text: Tito F. Hermoso / Photos: MB Press, Isuzu, Hyundai, VM Motori, JP Cariño, Brent Co | posted February 10, 2011 15:06

The diesel dilemma

The little engine that could

OM 636. Previous to the OM 636, diesel power was mainly understood in these islands to mean huge marine engines that power ships, slow revving engines that drive remote power generators and big displacement iron block power for trucks and train locomotives.

OM 636 engine


OM 636 is the code Mercedes Benz gave to the 1955 180D engine, the first diesel engine powered passenger car in the Philippines. You could consider it ahead of its time as the 40hp/3,200rpm iron block, cast iron head, push rod 8 valve 4-cylinder had thin walled stamped sheet steel and alloy manifolds and casings. It was not the slightest bit bulky nor heavy compared to the valve-in head and OHV engines that were common then. OM 636 traces its heritage to the gasoline powered 170V engines produced before the outbreak of World War 2.


Noisy, smelly and laughable

The Mercedes Benz 180D was indeed an anachronism in those post war days as most cars on Philippine roads were gasoline powered American giants and surplus USAFFE Jeeps. While the rest of motoring was carried on cart springs and Victorian era ladder frame chassis, the 180D had fully independent swing axles and uni-body safety cell in a far more compact package. With such construction it could take the country's bumpy roads at speeds that have 150hp behemoths crawling, left in the dust. And it could go further on a tank of cheap diesel fuel than any other 4-wheeled car of that time. High society laughed at it because of the cantankerous sound it made, the odor it emitted [its the fuel not the engine, dummy!] and tectonic body shaking it induced on idle. But it lent itself well to aftermarket air conditioning as the little diesel did not overheat. It proved itself durable as Mercedes Benz made a contest of owner cars, by sticking medallions on the grille to show that, regularly serviced, the OM636 could serve 360,000km and more without an engine overhaul. Just regular filter cleaning and oil changes every 3,000km, as oils at that time did not have high tech additives nor multi-viscosity. The first Oil Crisis triggered by the Suez Canal War in 1959 was to make the 180D a hero of its time.

Asian taxis

One of the early adapters of the 180D was the Asian taxi market. Soon, the 180D's competitors in Continental Europe arrived on the scene. Austin Cambridge, Morris Oxford, Peugeot 403 and 404 and Borgward arrived in small numbers in the taxi markets in many of the ex-British colonies in the region. Over in the Philippines, it was only a matter of time when Universal Motors would start local assembly of the respected Mercedes Benz models in the Philippines.

Surplus meets surplus

At the same time, the engine imports of the OM 636 began powering medium sized transport boats, such was its power to bulk ratio. The surplus WW2 Jeeps were also being chopped and stretched to be made into Jitney public transport. Out went the Willy's or Ford flat head 2.5-liter gasoline engine, replaced with the OM 636 which came with a 4th gear, one gear more than the national US standard.

Germany also rises

With the ascendancy of the Germany as a powerhouse economy, Mercedes Benz products were becoming expensive, even if loyal Jeepney operators were reluctant to try other brands, like Hanomag, Peugeot and Perkins. The first dollar crises of the economy induced Philippine transport operators to give cheaper engines from Japan a try. In time they now had a new favorite, Isuzu.

Here comes Japan

Isuzu like Mitsubishi-Fuso, UD Nissan Diesel, Toyota-Hino, diesel trucks were already familiar on Philippine roads as the sizable long term Japanese War Reparations trickled into a truck market dominated by Ford, GMC, IH, REO, Diamond T, White, Peterbilt and Chevrolet. Naturally, Mercedes Benz trucks also had a following thanks to the little 180D. Like Mercedes Benz, Isuzu ventured into small displacement diesel engines to power its mainstay light trucks. In time the Isuzu C190 and C220, became the default diesel engine installation for the light commercial and passenger transport vehicle market.

VM Motori diesel

Closing the gap

By now, diesel engines around the world were beginning to ape their gasoline counterparts. Advances in metallurgy allowed diesel engines to be designed and built like gasoline engines, reducing the weight penalty associated in toughening diesel parts because of the pressures and metal stress produced by compression ratios of 22:1 is far high than a 9:1 gas engine. Overhead cams and cross flow ports improved diesel performance too. With double the mountain of torque produced lower down the rpm range compared to a gasoline engine, judicious spacing of gearbox ratios meant that diesel powered vehicles no longer were slow of the mark. Their only disadvantage to gas engines is their short rpm range, some 2,000 to 3,000 rpm short of the average 4-cylinder gas engine.

Luxury diesel?

From the 70s to the 80s, Mercedes soldiered on in the local market as the only purveyor of diesel cars but the price of the 60hp 200D W123 with hub caps, bias ply, no tint glass, no radio, power nothing, 4-speed on the floor and a factory fit air con that cost as much as a Japanese sedan was way too stratospheric.

Isuzu Trooper

Smart move

Enter GM Pilipinas and Isuzu in 1980. Using the body shell of the Opel Kadett and a newly developed alloy topped 1800cc diesel engine by Isuzu, the diesel passenger car segment was reborn and the taxi market queued up in droves for the Gemini. Isuzu also prodded what could virtually be the green shoots of the SUV market with the 2-door Isuzu Trooper, running with the trusty workhorse, the C190 engine. This engine was so prevalent on Philippine Roads, that then Secretary of Industry Roberto Ongpin nominated it for local manufacture in the PEC Philippine Engine Corp. plant in the Cavite Export Processing Zone. The PEC made Isuzu C190 was to be the sole diesel engine as for the LCV market it was assigned to be one of the Eleven Major Industrial projects of the Philippine economy. Take note too that the same iron block Isuzu was to also be the seed of China's green shoots in manufacturing diesel engines.

Heating up

Isuzu's dominance of the passenger car diesel engine market was fully sewn up. Toyota introduced a diesel powered Corona silver edition, a "Silent L" diesel powered Hi-Ace and a diesel powered Crown, similar to the taxis in Hong Kong. Nissan introduced a front wheel drive Sentra diesel too. But Delta Motors' collapse put an end to Toyota's budding challenge.


Meantime, the rest of the world's car makers have been able to harness computer technology to enhance automotive diesel engine performance, economy and emission control. In Europe where diesel prices are almost at par with petrol. Despite this, passenger car usage of diesel was prevalent. Almost all engine makers were making lighter and quicker diesel engines for passenger car application. Opel, Mercedes Benz, BMW, VW-Audi, Volvo, Renault, Peugeot-Citroen, FIAT-Iveco, Perkins, DAF and BMC were applying high pressure common rail direct injection technology, multi-valve heads, turbocharging and intercoolers to mass produced diesel engines. VM Motori, Bosch and Magnetti Marelli were all engaged from engine to component design with the aim of improving diesel engine drivability. Other car companies sought to quick start their diesel engine programs by out sourcing to FIAT, Opel or PSA Peugeot Citroen.

The laggards

Diesel engines did not advance as much in North America as gasoline was cheap and diesel was thought to be only for trucks. South America was developing its bio fuels programs then, so government subsidies distorted prices putting diesel at a cost disadvantage. In strict emission control countries like Japan, car manufacturers didn't bother improving diesel engines as city ordinances kept diesel engine vehicles away from city centers. Thus Japanese car makers developed new diesel engines in other markets like ASEAN and Europe where there was better diesel engine acceptability.

Catch up, because of exports

As European diesel cars got better, Japanese and Korean car makers decided to enter the burgeoning European market by building to EU specs and clean EU diesel. When China's car market started to grow, China adopted more stringent Euro IV standards of clean fuel not only to reduce pollution in their country but also to prepare their engines for exports.

Mitsubishi L300

Now to modernize the fuel

As most of the motorized world moved up to cleaner Euro III and Euro IV diesel, the Philippines, along with other ASEAN countries that heavily subsidize diesel fuel for the public transport franchisees, could not move up to the cleaner standards. The never ending flood of reconditioned old diesel engines from Japan and Taiwan meant that diesel fuel can only be locally refined to Euro II sulfur rich standards, unless someone coughs up USD 1.2B for a new refinery. The high content of microscopic sulfur was necessary to cushion the valve seats of the old types of diesel engines. But this also meant very high levels of pollution, both the visible and invisible kind. The majority of the population has no choice but to breathe the foul air as the transport lobby behaved like the cheap fuel and reconditioned engines were an unalienable right.

Time to breathe better

All that smoke and malodorous emission was a symptom of incomplete combustion. Moreover, many non-OEM independent mechanics, ignorant of ECU's artificial intelligence and electronic diagnostics were quick to blame modern diesel technology as the culprit since they had lost business in manually repairing defects of the old pre-chamber engine design. It was actually a choice of having the cheap fuel dirty our lungs or dearer fuel that would enhance the efficiency of the new kind of maintenance minimal diesel engine. Other manifestations of combustion stress was the erratic crackling of the engine note at mid-range rpm, a sign that combustion was turning erratic because of the high sulfur content.

Nissan Neo Di


The other problem of Euro II diesel fuel is that it causes premature injector failure in modern crdi engines made for Euro III and Euro IV fuels. Some of the ASEAN made brands had difficulty with this as their mainstay pick up and MPV sales suffered engine problems despite regular scheduled dealer servicing. The Korean engine makers were to prove successful in solving the problem of making their diesel engines work perfectly fine for Euro II, III and IV fuels. BMW, Audi, Mercedes and Volvo were also ultra cautious of this and they took years of testing before they reconfigured their injection systems to deal with the dirty fuel of the Philippines. Besides the Navara, Patrol and Urvan, which use ASEAN diesel engines, Nissan can't fit the excellent Renault designed and built turbo diesel family for the new X-trail and Livina as Renault can no longer down-adjust its small diesel turbo engine.

Hyundai CRDI

Hope costs

Diesel engine vehicles are here to stay and the most sensible policy for nationwide fuel efficiency is to allow the oil companies to recover the cost in investing in making Euro IV diesel - yes, through a price adjustment. Meantime. Diesel engines that are configured for cleaners fuels will no longer need to be dumbed down. In time, the Philippine citizenry's breathable air quality should benefit from cleaner fuels run on cleaner modern engines. But first, the transport lobby has to be convinced that all that cheap but dirty fuel ingested in all our lungs is not good for their health either. Besides, clean diesel extends the shelf life of engine oil and oil filters making it worth while to use semi-synthetic lubricants.


Today's V-Power diesel and Turbo diesel with its more expensive additives is a step in the right direction, though they are not rated as genuine Euro III or Euro IV. At least, there is light at the end of what used to be a dirty tail pipe. The addition of bio-diesel additives have improved not just emissions but also removed the odor. Hopefully someday, our fuel finally measures up to the great advances in diesel engines ever since the the days of the OM 636.