the-oneil

Hi all

I understand the fuel consumption for both diesel & petrol is much worse in winter than in summer due to the drop in temperatures and therefore cold starts, but I was just wondering if diesels fair better than petrols in winter.

What I mean is, will the increase in fuel consumption be more noticed for a petrol than for a diesel engine during winter?

Thanks

hythe

Depends on the average length of your journeys - if you always do a long journey, the cold starts matter proportionately less. I would have thought that the cold weather would favour turbocharged engines - certainly my supercharged B5 loves the cold and wet air.

Major influence on economy is actually most likely to be just the slower traffic you have to deal with in rainy or snowy conditions.

jrsamps

Here in the Northeast, the gasoline contains an additive (a pollution thing) It lowers MPG by 2-4 -

skaffa

With studed tyres mine eats about 0,3 l/100 more. This when temperatures are mild but -15C or colder then Webasto heater eats about 0,5-1,0 litre more. These direct injection diesels don't generate enough heat!!

Skaffa

thebe

On a mixed short/long (city/150+ km) trips, last winter I actually got better mileage than this summer (my summery tires are 245/275 versus 225 wide winter ones). I only got the car last fall, thus this spring/summer I was surprised to see that the consumption is up 0.5-1 litres (of the best diesel fuel available here).

jet190rs

i heard gasoline/diesel is more dense at lower temps, so you're getting more fuel for the same amount at the pump. if this is true then it might offset the drop in fuel consumption....

Ray Hull

My difference in serious Northeast winter weather is only about .5 mi/gal (21.5>21 avg) and I attribute that to the 17" snow tires--both good in that I don't hammer it so much, and they are not as grippy and therefore probably roll easier.

Time on choke for me is minimal in that I am only about 5 blocks from the Interstate.

Cheers,
Ray Hull

Ricracing

My fuel consumtion is about the same.

In summer I have the 245/40 tyres which
gives the car worse mpg than the 225/55's.

Cold starts, of course, consumes more fuel,
but I have my car in the winter connected to
the DEFA heating system, so that's not a problem
either.

ImolaRedM

The air will be more dense. Think cold air intake. Fuel will still have the same energy. The engine will run less effieciently when the engine is cold, remember the old days when all engines had a manual choke? Once the engine warms up the engine sould run more efficiently in the winter than on a hot summer day. Humidity will also play a roll but that's another topic. As for Winter fuel mixtures in some states, there are areas now that use ethanol all year and MTBE has been - or is being - phased out. Ethanol has less energy than dino-juice but at a 10% mixture you may not notice much of a change. The two to four MPG figure seems high.