I found this specs on the internet...

Engine model 4G91
Displacement, cc 1496
Max.power (Net), kw(PS)/rpm 97 ps (71.34 kw) / 6000 rpm
Max.torque(Net), N*m(kg*m)/rpm 12.8 kg*m (125.53 N*m) / 3500 rpm
Power density 10 ??
Engine type Serial 4 cylinder DOHC16 valve
Engine information
Fuel system Electro- carburetor
Fuel type Unleaded regular gasoline
Compression ratio 10
Bore, mm 78.4
Stroke, mm 77.5
Fuel consumption at 10-15 modes, l/100km 6.2

While...

Engine model 4G15
Displacement, cc 1468
Max.power (Net), kw(PS)/rpm 91 ps (66.93 kw) / 6000 rpm
Max.torque(Net), N*m(kg*m)/rpm 12.4 kg*m (121.60 N*m) / 3000 rpm
Power density 9.01
Engine type Serial 4 cylinder SOHC12 valve
Engine information MVV
Fuel system ECI multiple
Turbocharger No
Fuel type Unleaded regular gasoline
LEV system (Low emission vehicle) No
Compression ratio 9.4
Bore, mm 75.5
Stroke, mm 82
Fuel consumption at 10-15 modes, l/100km 4.7

Why is the fuel consumption for the 4G91 engine so much higher than the 4G15 when both are 1.5l engines?
What does it mean by "Fuel consumption at 10-15 modes"???
Lastly, say I have a Satria, would it be wise to switch to the a 4G91 engine or 4G15 if fuel is my main concern???

Thank you for your opinion...

4g91 is double cam and 16valve ler. 4g15 is single cam and 12 valve only. the 4g91 accelerate is better than 4g15.

Wrong....

Actually, 4G15 is made to replace 4G91. There are a few types of 4G15 which incorporates SOHC, DOHC and even MIVEC technology. There is also GDI based 4G15.

The only thing is that 'our' 4G15 is the economical one.

4g91 is a good engine replacement for your 1.3 / 1.5 wiras. plug & play, no problems, power ok, lots of upgrade opportunities. the current price for the half-cut now is between 2.8 to 3.2k.

There are also another carburator variant of the 4G91. The 91 has DOHC layout, therefore more peak power. Yup, soulfly is rite, there's a DOHC 4G15 with the timing belt situated at the left hand side(driver's view). While the DOHC MIVEC version of 4G15 is implemented on the latest Colt. There's even MIVEC turbo for the Colt ralliart version. Nevertheless, i still think the EFi 4G91 is better than our locally produced 4G15P.

So the 4G91 is better?

Yup, overall it is better
Our economical 4G15 is way too underpowered

you'd be supprised how economical a efi 4g91 twin cam can be. the fuel consumption for an auto is less than our 4g15 auto

Juz wondering, how do you know how economical an EFi 4G91 Twin Cam can be??? Have you use it before???

"Our" 4G15 is underpowered and consumes more fuel because of Proton's "clever" idea to match it with a 3-speed auto gear box right? Or does it also suffer with a manual???

wow...where is the 4G91 original from (what car)?

Since it can fit into Wira/Satria (p&p), can fit into iswara as well?

4G91 if not mistaken are from Lancer with timing belt on passanger side one. and one of the mounting doesnt fits iswara/saga .. need to modify.. not clear if there is 4G91 for saga chassic.. maybe the carburator version ..not sure. :-).. but is a very common engine to transplant among those who wanted a better powerplant yet fuel economy.

it is mitsu 1.5 dohc engine. from mitsu lancer mx saloon.

have transplanted a few 4g91 for some wira / satria customers, all of them damm happy with the power & economy. one of them had the cams & ecu upgraded, even my 1.6 satria cannot catch that car:-P

as for iswara, too much work need to be done to fit that engine in. the mounting points need to be changed. done that before, don't intend to do it again. if u're really interested, my friend's workshop will do it for you.

normally how much will they charge for the engine include workmanship?
after swap engine, what else to do with the car. so roughly for complete setting how much? sorry to ask many questions because u said u done a few change for ur customer.

I found it in a 1993 Mitsubishi Mirage...it comes with automatic tranny...does it still provide good power and decent economy???

if u buy h/c den gonna services the engine and change some old part hardware. after transplant den gonna go inspection at puspakom and jpj approval. now transplant a 4g91 den settle everything gonna like RM5k.

dun worry, the power of 4g91 auto still good 1. still hv many thing to play n mod 1.

Wow...RM5000.00... I think after transplant, no money to "play n mod" d...

coz the h/c price is increase d mah. jz the h/c oso wan RM3k++ d lo...

If i remember .. for AUTO is around 2.8k .. Manual 3.3k .or maybe 3.5k .. that was months ago ..

3.5k + 1k (workmanship) + 500 (replace parts timing belt and so and so)... another few hundred for JPJ.. 5k ++ a bit .. .