First Hand Experience. Extra Passengers = Worse Fuel Economy
 

I just bought a Scan Gauge II 1 month ago and this device is really an excellent tool. Upon initial use, I have noticed all the things I have adjusted or upgraded to my car...But gosh I didnt think extra passengers would be so noticeable by my Scan Gauge.

My acceleration with 1 additional passenger increases my GPH! I have proven it to myself! I guess this would confirm the thought process that the more weight you carry....the more fuel you use! Just want to add this thought to this forum. Since I have a 4 cylinder vehicle...this is more noticeable.

Has anyone here noticed this on their Scan Gauge with an additional 4 or 5 passengers?

While I do not have a scangauge (yet) I have noticed a difference with carrying more passengers. My past two cars have been manuals (the ONLY way to drive!) and I definitely noticed an increase in strain while letting out the clutch. I would experience more stalls/close to stalling while carrying extra passengers. Same thing happened while using A/C. The A/C made such a difference that I ended up turning it off when I would first put the car into gear at a traffic light.

Now that I am into hypermiling though, the A/C doesn't even get used...!

I found that having passengers in the back seat or a fully loaded trunk can reduce fuel consumption (increase FE) on long highway drives. Weight on the back of the car will lower the rear end which in turn reduces the angle of the windshield and reduced total frontal area. I know it sound counter intuitive but most cars are designed from the factory with a lot of built in capacity in the rear springs for the extra weight of luggage and passengers. If you don't normally have anyone in the back (thats 90% of drivers 90% of the time) you could lower the rear end of the car by an inch or two to reduce drag. I saw 42mpg in a neon driving 80mph with 4 people and all our stuff on board as opposed to my usual 36-38mpg when I'm driving alone. Just remember to also adjust the angle of your headlights accordingly.

an extra passenger doubles your fuel ECONOMY!!!
 

First hand experience, carpooling saves lots of gas!!!

fuelmiser,

When accelerating from a stop, are you revving up your engine to the same RPM with passengers as the engine RPM without passengers?

well just multiply your FE by the ammount of passengers. by carrying extra passengers fuel used per person dramatically decreases, it may be the driver who has to pay for the fuel but overall fuel consumption per head decreases.

i usually feel a little guilty driving around alone

More passengers = less FE, especially when the wife is hot and has to have the windows down. :D

Well, if you can get away with your wife only rolling down the windows, maybe you should count your blessings. She could be insisting on you running the A/C and leaving the windows closed?

I have a ScanGauge II, and I have noticed that as I add passangers, my GPH goes UP. I drive a 2007 Yaris. When I have 5 people in that car, the milage reallyh goes down, at least by 15%.

It has been a mixed bag for me. On the one hand MPG goes down while accelerating but I have seen no real change while cruising on flat ground. I have also discovered that my car coasts better down hills with passengers. Hills that I have to stay in gear down while alone I can EOC down with a full load, so it kind of evens out the losses while accelerating or going up hills.

If I am doing my normal rural/hilly driving I don’t notice much change but in city driving it is way worse with passengers.