worsererer fuel consumption

[Top Cat]

In my opinion there is no way just changing the wheels to heavier ones would give 7 miles a gallon less. 

Surely if this was the case,  manufacturers would be making lighter wheels right across the board. 7 miles per gallon would be a lot of engine and fuel development me thinks 

Just to add my usual caveat though, i could be talking sh*t. 

[Greeners]

Thinner wheels/Tyres will reduce drag and help with fuel economy, but I like you TC do not believe lighter wheels would make as much as 7mpg................ 

The Prius has magnesium wheels but I'd be amazed if they made that much difference. Especially as they then snap on plastic wheel covers which must add weight!! 

[Hurdy]

Not talking s**t TC

When I had my 19" CH's on it made about .....zero difference to the fuel consumption

[Greeners]

I have also ran 19's and didn't notice a difference. 

[Top Cat]

MY works are 5lbs lighter per wheel than my monza's and my MPG didnt go up.   

Matsu it's probably coincidence, i would check my DV and get some logs done. 

[Greeners]

My fuel cons has suffered recently as every morning I am now using....................

Lights
Rear demister
Heated mirrors
A/C on occasion to clear the windscreen
And heater on full tilt

[Garth]

Thinner wheels/Tyres will reduce drag and help with fuel economy, but I like you TC do not believe lighter wheels would make as much as 7mpg................ 

The Prius has magnesium wheels but I'd be amazed if they made that much difference. Especially as they then snap on plastic wheel covers which must add weight!! 

7 mpg is a lot granted, but heavier wheels WILL make a difference. You may not notice it, especially if the wheels/tyres are not much heavier.
It's exactly the same as adding massive heavy brakes, you're adding rolling weight which will hamper performance and increase fuel consumption. By how much is debatable, but it's still a fact.

There are other factors at play here too, like how good your tyres are. I went from Continentals to Sunew's so I can't blame all the mpg los on heavy wheels as my tyres are sh*tE!!

[Greeners]

Thinner wheels/Tyres will reduce drag and help with fuel economy, but I like you TC do not believe lighter wheels would make as much as 7mpg................ 

The Prius has magnesium wheels but I'd be amazed if they made that much difference. Especially as they then snap on plastic wheel covers which must add weight!! 

7 mpg is a lot granted, but heavier wheels WILL make a difference. You may not notice it, especially if the wheels/tyres are not much heavier.
It's exactly the same as adding massive heavy brakes, you're adding rolling weight which will hamper performance and increase fuel consumption. By how much is debatable, but it's still a fact.

There are other factors at play here too, like how good your tyres are. I went from Continentals to Sunew's so I can't blame all the mpg los on heavy wheels as my tyres are sh*tE!!

Agreed, but as you have stated there is more than wheel weight to be considered if you have lost 7mpg.

[Garth]

Agreed, but as you have stated there is more than wheel weight to be considered if you have lost 7mpg.

Very true. I lost 4mpg for which I am splitting the blame between heavy wheels and crap tyres. We'll see how much (if any) I get back when I get decent tyres in the new year

[RedRobin]

....

I agree that any improvement won't be as much as 7 mpg but all the theory points towards some measureable improvement even if it's only 1 or 2 mpg. It's all fairly academic anyway because with lighter and sportier feeling wheels you'll tend to enjoy it more and drive faster, consequently using more fuel!

[Garth]

It's all fairly academic anyway because with lighter and sportier feeling wheels you'll tend to enjoy it more and drive faster, consequently using more fuel!

Surely that's not true. I thought we all modded our cars to make them more economical and that we concentrated on getting the mpg higher and higher, not the bhp
 

[RedRobin]

^^^^

Think ourselves lucky that we don't live in territories where modding cars isn't allowed and we are forced to drive very unexciting cars which comply with draconian rules hiding behind environmental reasoning.

I hate to think what will become of the petrol driven car and am really glad I've experienced nearly 50 years of its development.