slammedgs

I have noticed that my car gives me terrible gas milege...it's 1998 gs400 31k...my average consumption is around 11mpg (so it says on the navi) i live in brooklyn ny and drive around the city most of the time and i know that it is a V8...but 11 mpg is rediculous..i really think the car may need some mechanical work...tell me what u think

GS Doug

This is my first post on the forum. I own a '99 GS 400, and I average 20 mpg on combined city and highway driving.

D-MAN63

whoa 11 mpg?? That doesn't sound right. Better have a check with the fuel injectors or maybe the NAV is off

11 mpg is SUV range man.

bitkahuna

iTrader: (20)

If you're driving around Manhattan then I could easily believe you only get 11. I expect you spend more time stopped, either in traffic or at lights, than moving.

I get 15 around town and I know it moves a lot better around here than in the NYC area!

nikogs400

Its possible..

I also live in Brooklyn and I track my mpg manually and its been as low as 13 mpg (using power mode e-shift and lead foot) up to 21 mpg (normal mode high speed cruising -highway only)

Check it manually and see but I think 11 is a little too low

Just my 2 cents

lexguynj

ALso keep in mind the AC and anything else you are using in the car. Driving around the city with the AC on full blast definitely will cut down on your MPG.

However 11MPG still sounds very low.

Good luck!

gs4to4

During a trip to florida, I noticed that the GS400 guzzled gas much more when I cruised at about 80-85 compared to 65-70. Anyone have specs for this?
It seemed like it was eating fuel almost twice as fast!
As for driving with the A/c on, how much does it really take from the MPG? I heard that at highway speeds, it saves more gas to run the a/c instead of having the window open because of air drag.
Anyways, I should be the last one talking about fuel economy because I probobly average 8 mpg considering that I floor it of every light

mooretorque

11 is low........15-16mpg around town even with aggressive driving is more like the norm. If the injector cleanter doesn't work, you've got some issues with your service dept. Should be warranty work. For that matter, since whatever is going on no doubt affects your emissions (the vehicle's, that is), you've got what amounts to an EPA warranty up to 100k miles even if, by chance or mileage, you power train warranty has expired. Unless you've moded your engine. Good luck.

bitkahuna

iTrader: (20)

Double the consumption at 80-85 instead of 65-70? That makes no sense. I got 23 I think when taking a long trip mostly at 80.

A/C has negligible overhead on gas consumption unless you're stopped. And yes, opening a window is going to be worse.

D-MAN63

I never knew that

QBranchCars

I also get 15-16 mpg around town, and I have the SRT HFI. At best, I get around 21mpg on the hiway. I know that I get better mpg than than the same setup with a torq converter, proven on just freeway driving.

daku

From what I understand, after a certain speed, most cars actually do get fewer MPG. I had heard that it was between 35-45, but that number just seems to low for the GS. I'd guess that the optimum "condition" would be around 55 in 5th gear.

As I understand it, the higher the gear, the more efficient your car w/ regards to MPG. However, after a certain speed, "the atmosphere" serves as a drag on the car. This creates a situation analogous to running in a swimming pool. This is also why its more efficient to use the A/C at highway speeds. The extra gas consumed is marginal and much less than the amount used is to overcome the loss in aerodynamic efficiency from opening your windows (and the sunroof).

That having been said, your gas consumption couldn't have doubled when you increased your speed by 10-20 miles.