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Difference btwn 08 FEH and 08 MMH

Created December 5, 2007, at 1:24 am by djharfer

I have test driven both cars now and one major difference I notices was that the MMH engine was VERY loud. Accelerating from a dead stop and the engine got up to 5K rpm and almost seemed to struggle.

Tonight I drove a FEH 08 for the 1st time and it was 100% different. It only got up to 3K rpm under the same type of test and was MUCH quieter. No struggles at all

I wouldnt expect this normally considering they should basically be the same vehicle, or so I think (?). The dealer did tell me that one difference in the MMH is has better internal sound proofing, which confuses me even more.

Looking at the reviews on Edmunds, 2/22 MMH 08 reviews mention noise as a complaint. Yet on the FEH 08, 0/39 complain and 3 even specifically mention how quiet the car is!

So, my question is whether or not this is a real know issue or just that there was a reason that there was 1 MMH left on the lot and I heard why? :)

Thanks in advance

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GaryG
Senior Member

4 years ago

Both vehicles have the same engine with the same programming. The fact that you only got up to 3,000 RPM's in the FEH and went to 5,000 RPM's in the MMH would make a very big difference in noise. Also, both vehicles have programming to warm the engine faster within the first few minutes from a cold start. This programming could have been completed in the MMH, but not in the FEH. The PCM cold start programming works by using the electric motors to produce most of the torque while accelerating so the engine timing can be retarded. Retarding the timing and keeping the engine at an idle causes combustion in the cylinders to burn hotter. This speeds up the warming of the CAT converter faster to reduce emissions much quicker. The MMH could have completed this programming, but may not have been warm enough for ideal performance.

Remember this special programming if you purchase either vehicle and allow slow acceleration to warm the engine faster. You will go EV much quicker and your mileage will be better.

GaryG

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djharfer
Junior Member

4 years ago

Gary - What you are saying makes logical sense. I would expect the same performance, OTBE

I just cant seem to explain my first hand experience. Even after 20mins of driving the MMH, the excessive noise remains and never did it get below the level that I could get out of the FEH.

My plan at this point is to drive another MMH and see what happens.

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GaryG
Senior Member

4 years ago

djharfer;14408 wrote:
Gary - What you are saying makes logical sense. I would expect the same performance, OTBE

I just cant seem to explain my first hand experience. Even after 20mins of driving the MMH, the excessive noise remains and never did it get below the level that I could get out of the FEH.

My plan at this point is to drive another MMH and see what happens.

One other thing I heard causes a louder noise is a loose air intake scoop. One person said he removed his to pull in under the hood warm air to improve mileage in cold weather. He couldn't stand the noise of the engine so he reconnected it.

GaryG

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