Pajero Engine Specs

[Frederic]

Many people have doubts about which engine type of Pajero they should buy, and specifically which will perform best in the desert. Mitsubishi provides the engine performance curves on their brochure but as they are not comparative i wanted to compare the 3.5 6G74 , and 3.8 6G75 engines from the 4th Generation Pajero (2008 till YTD). 

 

In above charts you will see the performance of both engines with Output in Kilowatts and Torque in Nm. When you layer these over each other you will get the following:

Conclusive results:

Output kw or Horsepower: The 3.8 engine performs the best with a max output of 250Hp at 6000rpm, while the 3.5 engine reaches its peak output of 189Hp at 4,750rpm. Up to 4500 rpm both engines react and perform quite similar, which would indicate for driving in the dunes they will perform similar, except for hill climbs where you will need to go beyond that rpm. The 3.8 clearly has the upper hand at that point.

Torque: Again the 3.8 shows higher torque values with a max. of 327Nm at an rpm of 2,750rpm, while the 3.5 model reaches 306Nm at 3,750rpm. 

In Carnity Offroad Club we have seen 3.5 Pajeros performing very well, and while the 3.8 engine has the upper hand when it comes to high-rev hill climbs, they are both capable offroad engines that will do well in the right hands. 

Purpose of this topic is to consult your engine performance and try to find the "sweet spot" in at which your engine and torque level would be the best for that particular application. From these charts it is quite clear that the 3.5 engine needs to be used more on a lower rpm range and with the proper momentum.

Of course these values are theoretical and one will find big differences between each vehicle depending on how well it was maintained, how old the engine is, or if there are issues with the vehicle (spark plugs, injectors, air filter issues). 

We have plenty of Pajero owners, so let's discuss and learn from each other !

 

 

[Wrangeld]

@Frederic  nice to see what the difference in the engine delivers. I guess when coupled with the SWB body, that performance differential expoains why and how the SWB climbs adequately without the use of tiptronic and when TT is engaged how this has capabiltiies that are more challenging in the LWB. 

Since I bought my little Paj, and the gear change problem was solved it power is not the issue: using road tires as opposed to something more aggressive and matching shocks/springs to optimize the power would transform the experience without moving the car into the modified classification. 

I am a some stage thinking about a unichip to rid the engine of the shift at 5200 rev (other posts cover this), which I think will potentially create a pretty perfect power weight ratio (to make up for the additional weight that will be added by a new crash plate!) 

[Frederic]

57 minutes ago, Wrangeld said:

@Frederic  nice to see what the difference in the engine delivers. I guess when coupled with the SWB body, that performance differential expoains why and how the SWB climbs adequately without the use of tiptronic and when TT is engaged how this has capabiltiies that are more challenging in the LWB. 

Since I bought my little Paj, and the gear change problem was solved it power is not the issue: using road tires as opposed to something more aggressive and matching shocks/springs to optimize the power would transform the experience without moving the car into the modified classification. 

I am a some stage thinking about a unichip to rid the engine of the shift at 5200 rev (other posts cover this), which I think will potentially create a pretty perfect power weight ratio (to make up for the additional weight that will be added by a new crash plate!) 

True. The Unichip is currently the only viable solution for getting rid of the upshift issue in your generation Pajero. 
 

A 8mm aluminum bash plate doesn’t weigh a lot. I think 10-15kg at most.

[Rizwan Waheed]

@Frederic Thank you very much for your detailed comparison. No doubt a little extra is always better if I compare with my Pajero i.e.3.5 Ltr.

I have always struggled while climbing hills, but other than that. I have started loving my baby elephant . 

up till now, I am driving it as a complete stock. But taking care of engine Oil / Air filter and changed spark plugs once. however after driving with regular tires in desert, I have started feeling a bit wobbling in my tires at the high speed on the highways. Got the Alignment and balancing checked, had been recommended to change the tires. 

apart from that, enjoying this LWB 2006 at its fullest. Truly I was lucky to got it agency maintained by the previous owner. 

Cheers.  

[Frederic]

2 minutes ago, Rizwan Waheed said:

@Frederic Thank you very much for your detailed comparison. No doubt a little extra is always better if I compare with my Pajero i.e.3.5 Ltr.

I have always struggled while climbing hills, but other than that. I have started loving my baby elephant . 

up till now, I am driving it as a complete stock. But taking care of engine Oil / Air filter and changed spark plugs once. however after driving with regular tires in desert, I have started feeling a bit wobbling in my tires at the high speed on the highways. Got the Alignment and balancing checked, had been recommended to change the tires. 

apart from that, enjoying this LWB 2006 at its fullest. Truly I was lucky to got it agency maintained by the previous owner. 

Cheers.  

If you decide to change the Tyres, go for something like the Geolandars AT. You won’t regret it.

[Rizwan Waheed]

@Frederic Copy that.

[Rahimdad]

Thanks @Frederic for a very well explained post on the power delivery of the 2 engine options. However older models of Pajero also came with the 3.0 litre engine which seems a bit underpowered on LWB versions, but the torque delivery seems excellent but on higher RPM as shown on the 3.5 litre version. Engine power is not the only thing to look at as delivery of the power is also shown on the curve.

One more thing to take care is pre 2014 models 3.8 litre engines came with the new 5 speed auto gears, but the 3.5 litre models came with the old 4 speed autos. From 2014 onwards both models received the same new 5 speed auto technologies. I believe this also makes some difference.

[Frederic]

7 hours ago, Rahimdad said:

Thanks @Frederic for a very well explained post on the power delivery of the 2 engine options. However older models of Pajero also came with the 3.0 litre engine which seems a bit underpowered on LWB versions, but the torque delivery seems excellent but on higher RPM as shown on the 3.5 litre version. Engine power is not the only thing to look at as delivery of the power is also shown on the curve.

One more thing to take care is pre 2014 models 3.8 litre engines came with the new 5 speed auto gears, but the 3.5 litre models came with the old 4 speed autos. From 2014 onwards both models received the same new 5 speed auto technologies. I believe this also makes some difference.

Thanks @Rahimdad

Below i have added the 3.0 SOHC 24 Valve engine specs as well.

 

 

And some detailed explanation on how the MIVEC system works on the 3.8 engines (taken from 3SI.org):

The MIVEC system features separate cam profiles for high and low engine speed modes, which translates to higher maximum power and increased usable torque in the widest variety of driving conditions. Under low-rev conditions, MIVEC selects the smaller cam profile, yielding medium lift on the cam profile which provides stable combustion and lower emissions. But when the throttle is opened wide and engine speed reaches 4300 rpm, MIVEC allows the intake valves a longer duration and longer stroke, thus providing maximum and efficient power and torque over a broader range of engine speeds.
The enhanced power output of the MIVEC system is achieved by its ability to vary the lift and duration of the intake valves. In the MIVEC system, there are three distinct cam profiles that create two engine modes: a low-speed mode, consisting of low- and mid-lift cam profiles; and a high-speed mode. The low- and mid-lift cams and rocker arms – which drive separate intake valves – are positioned on either side of a centrally located high-lift cam. The high-lift cam is directly connected to a T-shaped lever, which controls valve lift and duration of both intake valves in the high engine-speed mode.


At lower engine speeds, the T-shaped levers connected to the high-lift cams reciprocate freely without contacting intake-valve rocker arms, thus allowing the low- and mid-lift cam lobes to control corresponding intake-valve lift and timing. The intake rocker arms contain internal pistons retained by springs in a lowered position at less than 4300 rpm, to avoid contacting the high-lift T-shaped levers. The benefit of the dual-profile low-speed mode is to induce swirl within the cylinder, which helps create stable combustion and improve emissions.
The high-speed mode opens the valves longer due to its higher lift. At high engine speeds, the pistons within the rocker arms elevate when MIVEC sends increased oil pressure through an oil control valve. The high-lift cams’ T-shaped levers are then able to directly contact the elevated rocker-arm pistons, overriding the low-speed cam lobes and fully controlling intake-valve lift and duration.


The switch occurs at approximately 4300 / 4000 rpm 4G69 / 6G75), when the powertrain control module opens the valves longer to increase the amount of intake airflow, resulting in higher engine output. More precisely, MIVEC switches to the higher cam profile as engine speed increases, and drops back to the lower cam profile as engine speed decreases; the output torque of the low- and high-speed modes overlap for a brief period. This also means that the cam switch operation is transparent to the driver, who is simply rewarded with more power.


Under low-rev conditions the low- and mid-lift cam lobes drive the intake valves, providing better fuel economy and lower emissions. But when the throttle is opened wide and engine speed increased, MIVEC gives the valves a longer duration and higher lift, thus providing maximum and efficient power and torque over a very broad range of engine speeds. Despite its technological complexity, the basic workings of the MIVEC engine system can be expressed quite simply: MIVEC alters the cam profiles, tailoring engine performance to suit your driving needs.

 

The MIVEC system was made to compete against the VVT-I (Toyota) and VTEC (Honda systems).

 

The engine on my little blue is a 3.0 12Valve, so performance is even lower. (about 150 Hp at 250 Nm). Have seen an engine curve on the internet a long back but can't seem to find it anymore.