I am new to the boards here. I have not yet ran across anything about how much the mpg figures go down when carrying one to three passengers. In my checking on regular cars in past it seems to knock the mileage down 1-2 mpg with a passenger.

 

i dont have numbers for this, but i would think that for the civic hybrid, carrying passengers would decrease mpg more than it would for a regular car

say if you lose 10% mpg (this is not realistic) for one extra passenger, and your car gets 25 mpg normally, then you would have a 2.5 mpg drop. for a 48 mpg car like the hch (cvt) you would have a 4.8 mpg drop, nearly twice that of the regular car.

but the real mpg determination is where you drive and how you drive. weight is a factor, but only one among others. driving aggressively or on a hill alone will net you lower mpg than driving sedately on a flat road with passengers.

this brings up a question - will a small increase in weight (some extra cargo or one extra passenger) actually help increase your mpg if you have to brake more often on your route than accelerate? wouldn't the extra mass = extra momentum = longer time for braking and regeneration? i would think that given enough non-stop travel time at a constant speed, the initial extra use of gas to accelerate the more massive car would be negated by the extra savings of momentum - what do you think?

 

I believe another factor is psychological, like peer pressure from the other passengers.

I will pay more attention to my driving technique when I'm by myself. With passengers in the car, I'm distracted and tend to drive with the flow of traffic (however fast that may be).
The passengers normally don't have the same level of patience as me, and want to get to the destination as quickly as allowed.

The extra weight is only a factor when accelerating, so if it's all freeway it won't hurt as much. Once the car is up to speed the weight is not a penalty. Stop and go will kill MPG's with the passengers.

Regards,

 

that's true - i tend to drive faster and use less gas-saving techniques when carrying passengers, who are used to driving quickly and getting to their destination promptly. so i guess it can be a psychological thing too

 

Read this in an article recently:

"Every 100 pounds of weight in the trunk decreases fuel efficiency by about 2 percent."

I would assume that is the same for passengers. So three passengers averaging 150 pounds each an with the driver also, that's 600 pounds, so that would be about 10% reduction in MPG.

See the whole story here:

http://www.potomacnews.com/servlet/S...82227699&path=

 

thanks lars-ss

it makes more sense to say that 5 total people in the car versus only 1 (the driver) would achieve 10% reduction in mileage, though unless you like the benchmark mpg to be acheived by a driverless car.