Fuel Economy in traffic

[bobski1]

Recently changed work locations and my commute not has me sitting in quite a bit of traffic. Wondering if people also see a horrendous drop in fuel economy/miles remaining when in traffic or if there was a technique/method to inch the car along. I've tried just lifting off the brake and allowing it to roll forward slowly and also gently pressing the accelerator and neither seems to be any better than the other.

It did for about a month do really well but I think it meant not actually fully lifting on the brake but not sure if that is any good long term for the discs/pads.

[Dannbodge]

I see a massive drop.

Goes from 30mpg tank average with no traffic to 23mpg tank average with traffic.

In previous cars, start stop has improved this as you can roll with the engine off.
With no start-stop you're never going to improve it. Even leaving the engine idling and rolling will save next to nothing.

[ChocolateFrog]

When you're stationary you're getting 0 mpg and then likely single figures for the initial couple of seconds accelerating.

That will drop you're average over steady driving. Get an EV if it bothers you.

[Pica-Pica]

A hybrid will help massively here, as will an EV. Playing around with an ICE is just fiddling around the edges, with no recognisable or sustainable improvement in mpg.

[98elise]

ChocolateFrog said:

When you're stationary you're getting 0 mpg and then likely single figures for the initial couple of seconds accelerating.

That will drop you're average over steady driving. Get an EV if it bothers you.

This. ICE's consume/waste energy just to run. To get anything like reasonable mpg you need steady driving in a high gear, so the complete opposite of stop start traffic.

[_Hoppers]

Pica-Pica said:

A hybrid will help massively here, as will an EV. Playing around with an ICE is just fiddling around the edges, with no recognisable or sustainable improvement in mpg.

GT9 has just posted this in and EV thread. I would have expected and EV to perform much better at low speeds.

GT9 said:

JonnyVTEC said:

Peak power is quite different to continuous power rating in an EV.

Unlike an ICE.

The end.

Cruise power for both EVs and ICEs isn't very high, unless we are talking 100 mph ++.

At 70 mph on a flat road, a model 3 only requires about 17.5 kW or 23 bhp to maintain speed.

This curve shows the energy consumption per mile.

Cruise power (in Watts) can be calculated by multiplying the speed by the Wh/mile value from the solid red curve.

Data is for 15C ambient temperature.



And for the 'weight is absolutely everything' folks, the car, all 1.8 tons of it, is achieving 160 mpg at 70 mph.

The dashed red line is the theoretical consumption without the mass of the battery, about 8% better at 175 mpg.