Turbo or not to Turbo??
 

I am looking at a '95 E300 diesel. The car is a 6cyl. 3.0 liter engine. I don't think that these motors were turbocharged?? I am also looking at a '93 E300 5 cyl. 2.5 Turbo. My question is does the 2.5 td have more passing power compared to the larger 3.0 liter. Any help in making a decision would be much appreciated.


Thanks Gary

Ps. Thank you Leathermang for the smart ass comments on previous posts, a little education never hurt anybody

The 2.5 turbo, I'd imagine, would be similar in passing power to the E300. If all figures are correct.

121 bhp @ 4600 rpm 165 lb/ft @ 2400 rpm(2.5T)
136 bhp @ 5000 rpm 155 lb/ft @ 2600 rpm(3.0NA) weight is similar

It's really hard to tell. I don't have the dyno charts in front of me. I suppose it depends on how well the car was serviced. Of course that is most usually always the case regardless.

BTW, if you ever plan on juicing out some power, then the 2.5 turbo is your best bet. However the '93 300D has an ECU that requires that new fangled techno crap "chipping". I'd much rather prefer a wooden-edged screwdriver instead of a circuit board, myself.

I guess it depends on what speed, and when the torque curve drops off on the engine. I know a NA OM603 engine has a torque curve that diminishes after 2400 rpms, and a turbo 603 is just in the initial stages of it's upper rpm "thrust".

If the E300(OM606) is at all similar to the old non-turbos, then it is the weaker car on the highway by a large margin(despite the hp). The 2.5 turbo should be in it's prime on the highway.

Yes, I know you’re asking about a 602 vs. 606, but…
 

As an owner of both a 617 and a NA 606, I can tell you that the 606 does not have as much torque down at the lower RPM’s. BUT if you spin it up, it acts more like a gasser & dives for 5000 RPM’s making more & more power as it goes (unlike the 617 that runs out of steam at higher RPM’s).

If you are on an acceleration run with the 606, it’s great – smooth as silk and plenty of power. Where I notice the biggest difference is when poking around in slow freeway traffic – if you get caught at low RPM’s there isn’t a whole lot of torque to pull you up to the traffic that’s pulling away… But if you downshift & rev (either kickdown or manually) it scoots right along. I love this car. And I still love the old ’84 as well, but it’s really apples to oranges.

The 2.5 turbo does not have an ECU that controls fuel delivery - the ECU system in this car is responsible for boost, EGR and idle speed control.

The 2.5 turbo boost control system makes the car seem faster than it really is - turbo spool-up is very fast. I've not driven a non turbo OM606 but I agree with the previous poster, I suspect they would be about the same.

Now if you are really interested in a little more power look for a W210 OM606 turbodiesel...

Actually I always believed that '93 was the specific year that Mercedes first implemented ECU's controlling fuel management.

I thought that the earlier model 2.5 turbos were governed in the sense you refer to. BUT I do not own a 2.5 turbo, so I cannot make claims to hearsay.