Anybody have an idea why the IS300 has such a horrible fuel

I am also wondering, why did they use the I6 iron block here in USA? The aluminum 4 cylinder makes just as much horsepower, and its a lot lighter

because it has an auto, and because lexus crimped the e manifold, making the motor 10hp less efficient. the 2jzge motor never had that good of gas mileage in the supra, and the lexus is about the same weight as a non turbo supra.
i think with some refinement, they could either get better gas mileage or more power out of the motor, without changing too much of it.
has anyone kept track of MPG and documented that is was actually this horrible?

Does it help to put the car on "Normal" instead of "Power"?

PMD911: Yes, leave it on normal and don't use e-shift if you want the best mileage. However, I don't think it makes enough difference to really matter if you want to enjoy your car.

i think one of the reason's why lexus decided to make this car's exhaust more restrictive and decrease horsepower was to be one more selling point for the GS300. For some people, it might be a detracting factor to know the car your paying ten grand more for had the same horsepower. I know 5 hp is not a big deal but it one way to differentiate between the IS and the GS even though their using basically the same motor. I'm lookin at it from a manufactur's/dealers' point of view anyway.... .02

The auto trans hurts mileage.

The 3270+ lbs hurts mileage.

The agressive rear end gearing (3000RPMs+ typical on the freeway) hurts the mileage.

The soft performance tires might hurt mileage too.

Other than that, it is a mystery...

Originally posted by TEG:
The auto trans hurts mileage.

The 3270+ lbs hurts mileage.

The agressive rear end gearing (3000RPMs+ typical on the freeway) hurts the mileage.

The soft performance tires might hurt mileage too.

Other than that, it is a mystery...

Click to expand...

TEG my sister's tiptronic A4 2.8 quattro has all wheel drive and weighs 3505 lbs and gets 27mpg on the highway, so I doubt that the weight is a real issue... Especially considering that bigger GS400 gets nearly the same fuel economy as the IS300... I think the Final drive ratio is the Culprit..
Eric...

[This message has been edited by EricK (edited November 20, 2000).]

becuase your mom sat in it and it screwed up the mpg.