(G) Larger wheels decrease fuel economy:Discuss

Could be, but why more than 10 percent on what are supposed to be the same mechanicals.

Cheers

Gormless Cretin

Not that we're interested in the i10 but they do make an interesting point about wheels and co2/emissions

http://www.autoexpress.co.uk/carrevi...undai_i10.html

Jim

What Mark is describing is NOT unsprung weight.

Think of it like this. You've got a bike wheel in your hand and you spin it while you're standing still. You've got to overcome the interia right? Then you start running with the wheel. You now weight extra so you also need to overcome even more inertia. So you have to accellerate the wheel up to speed twice in effect.

Unsprung weight isn't just the hub, wheel and brakes either. Anything that's bolted to your car is considered as being half unsprung also. So a suspension strut is considered half unspring but a disc is totally unsprung.

forget all that

1 two different cars
2 different fuel from different fuel stations
3 loan car or demo what ever it was has more than likely had it's head kicked in buy prospective buyers
4 the particulate filter may have been blocked on the demo short journeys no time to regenorate rite
5 it may have just had it's head gasket replaced you know the recall
6 the ecu may have a different map on it it's when cars are new that fiat are constantly updating it to improve things and iron out faults
7 tyre pressures may have been different
8 tyres may have been different
9 brakes might have been seised sitting around at the dealer ship and having it's wheels cleaned with that horrible acid stuff
10 air temperature at the time
11 humidity at the time

there are just so many variables it's easy to account for the 10 percent fuel difference

Quite

Forget all that.

I didn't actually say that going up one inch on your rim size was responsible for the 10% difference in fuel economy. I was just saying that Mark Elvin was right in what he was saying.

It is nice if you read posts before replying to them.

it's also nice to be on topic and not try to rile up other users all the time

i was not trying to imply what you said was wrong just diverting the threat back to it's original topic

Damn! My plan to take Fiat down by making people on Fiatforum realise that a bigger wheel will slightly decrease fuel economy has been discovered

Mark described the fact that a larger/heavier wheel requires more energy to be accelerated. White500 said that was not the case and I simply clarified the theory behind it all.

Not quite sure what I've done to deserve your attention. I'm most flattered but already spoken for.

i never said that either your just attention seeking now

troll

how can someone blow such a simple sentence (forget all that) witch was not meant in any way to offend into such a big thing let it go i told you already it was not meant in the way you thought it was

Chimera

Saying for people to forget someone's post is not the same as saying lets get back on topic. If you look at the thread it was all relevant talk. We're all here to learn stuff and explain things to others. I'm more than happy to sit back when I don't know anything about a particular topic and I'm equally as happy sharing my little bit of knowledge when I feel I can. That's what a forum is all about.

You seem to think I'm here to rile people up for some reason. At the end of the day this is a discussion forum. People are going to disagree. I don't see any point in getting riled up because someone disagrees with me as long as they don't make insinuations or throw insults around.

you are quite abrupt and confrontational, not everyone knows about isaac newtons laws of motion.

wheels are unsprung wieght, ( prove me wrong )

Why would I want to? That's what I said

You are correct, they are.

But, increasing a cars unsprung weight will not make it use moree fuel.

Although, it's unlikely that a 10% increase in fuel used could be accounted for by larger wheels (unless you went to 22's or something silly)

Seems we agree on something again Make sure this doesn't happen again

That's why he probably comes into the 500 section so much. He'd feel at home with that attitude, lol!

Mr Very UpFront and Confrontational!

Jim