3.1L - Unusually High Fuel Economy Possible?

Remember that fuel economy "numbers" are relative values and do not necessarily directly reflect what one would experience in real world driving. I can relate that my 3.8's in a 1998 GP GT, a 2004 Impala LS, and a 2001 Buick Lesabre do indeed achieve mileage that is almost indentical to my 2001 GP SE 3.1 on the highway, not in the city driving. There are two reasons for the equivalent highway mileage: 1. The gearing, for example, in my 2001 GP SE and 2004 Impala are different. The 3.8 would turn about 2,000 RPM at 80 MPH and the 2001 3.1 turns about 2,300-2,400 RPM at the same speed. The increase of 300-400 RPM for the 3.1 at the same speed as the 3.8 L results in approximately similar gas mileage from the smaller motor versus the 3.8 at the same given speed. 2. The increase in RPM for the 3.1 motor at the same given speed probably results in similar horsepower being generated from the 3.1 versus the 3.8 at a given highway speed, thus similar mileage at a crusing spreed.

There is and has been a big difference in the city mileage that I have experienced with my current 3.1 SE versus the aforementioned 3.8 motors. Around town driving by the 3.1 motor is much better than any of the 3.8's I have owned. I have driven a total of 250,000 miles since 1998 with all four engines in total with the current 3.1 being the most at 100,000 miles.

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Originally Posted by jbamonte

2. The increase in RPM for the 3.1 motor at the same given speed probably results in similar horsepower being generated from the 3.1 versus the 3.8 at a given highway speed, thus similar mileage at a crusing spreed.

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I still am wondering where you get all your "Logic" from. The 3.1L is no where near the same as the 3.8L and has no where near the same horsepower period.

:th_yawning: When are you going to figure this out. There is a spread of at least 20HP between them sometimes more.

So how is that going to get you unusually high mileage?

Heres how you get good mileage:

Step one: buy a light aerodynamic car with low rolling resistance.

Step two: Drive like a grandma.

Step three: Do not brag about it because you drive a grandma car and drive like it too.

Enjoy

Are you delusional? 20 HP difference in today's engines is nothing in a 3,500 lb car. The 20 HP difference between a 3.1 and 3.8 is at PEAK horsepower RPM, not at 2,000 crusing RPM. Stop with all this nonsense about the HUGH differences in a NA 3.8 versus a 3.1-It's not that big. In fact it is VERy small!

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Originally Posted by jbamonte

Are you delusional? 20 HP difference in today's engines is nothing in a 3,500 lb car. The 20 HP difference between a 3.1 and 3.8 is at PEAK horsepower RPM, not at 2,000 crusing RPM. Stop with all this nonsense about the HUGH differences in a NA 3.8 versus a 3.1-It's not that big. In fact it is VERy small!

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its 25 horsepower and no, its not a big difference.

but you missed my point.

don't try and have a fuel efficient 3500 lbs car. Its not physically possible. The more mass, the more power is required to move it. VERY simple concept.

Get a light car then try again.

You are correct that fuel efficiency is a direct result of mass as well as HP. My point is that either engine is pretty fuel efficient in a 3,500 lb car that can get 30 MPG which is very impressive even by today's standards. For old technology, both the 3.1 and the 3.8, are pretty decent mileage wise if you drive the car like it was not just stolen.

direct injection is the FUTURE

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Originally Posted by matt5112

direct injection is the FUTURE

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This. 3.6 liters, 300 hp from V6 Camaro.

I get 23 mpg average per tank.

I'm out.

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Originally Posted by realdiehl

This. 3.6 liters, 300 hp from V6 Camaro.

I get 23 mpg average per tank.

I'm out.

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But its ancient tech. :th_thumbsup-wink:

I get... not enough. :th_jester:

I am getting on average 24MPG out of my 03 SE. I am at 330 to 350 miles with 1/4 of a tank left. I have only had the car for 3 weeks now and tomorrow will be my third time filling it back up. I drive a 70 mile round trip to work 4 days a week. I would like to get maybe 26 or so....

Ok I filled up and I am getting 25.61 MPG out of my SE. Is that the norm?

depends on a million and one different factors.

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Originally Posted by matt5112

The high value engine is based on the 3100/3400...

ANDDDDDDDDDD the 3800 was put to rest because the answer to fuel economy is direct injection and that happens to be easier with a smaller engine and DOHC because you have more space in the combustion chamber with more but smaller valves.

The LSx is there just to prove that OHV can still make stupid power... So don't knock OHV so quickly.

Ward's 10 Best Engines - Wikipedia, the free encyclopedia

enjoy.

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even the LS Motors are going the way of the dodo here soon. i do believe its 2012 GM will debut their new lineup of V8's

That.....




Is my response.