V70 spoiler

A spoiler can only work by increasing wind resistance and converting that to downforce. They really don't do much under 100 mph. How much did it knock your gas mileage down. If it didn't, then it isn't doing anything.

Race cars use them at speeds of 150 to 200 mph, not highway speeds. Most street cars just have them to impress their friends, not for function.

Precisely! My V70 came with a factory-fitted spoiler from new. It looks nice, but I'm not convinced that it has any real *practical* value.

Not trying to knock the original poster... Sometimes when you buy something, and you excpect it to do something - even when it doesn't you just have a consious belief that it is in fact making a noticeable difference. People who don't know you have it won't feel it, and they probably won't even if you ask if it made a difference,they will probably be humouring you when they say "ohh yah, I can really feel it". It's an actual psycological thing that's going on.

[Bonnet Lock] (Mon, 4 Oct 2004 23:30:06 +0100):

Well, the practical value can be that the car gets less dirty on the back when it has a spoiler..

Yes, that may well be true. I was thinking more in terms of handling - where the aerodynamic forces generated by the spoiler (at speeds legal in the UK anyway!) are too small to have much effect.

I think your mixing-up spoilers & wings. Spoilers do just that to the ariflow, thus they do add drag. A wing is what a racecar has & is the upside-down version of an aircraft wing. It is a low-drag way to get downforce, that's why racecars use them. The V70 spoiler is very much like a wind, therefore I think it does not add much drag. Example:- standard V70 quote Cd is @0.3-0.31 & V70R, which comes with the spoiler as standard, has a quoted Cd of 0.35. This is with extra intakes in the front, so I guess the spoiler adds very little drag. It should also work well at any speed above 70mph if I had time to do the maths I could prove it, suffice to say that drag is cubed with increasing speed & around 50-70mph is more significant than other forms of drag. There, I think I've made my point.

"S. M. Henning" wrote in message news: snipped-for-privacy@news.isp.giganews.com...

In my defence I can say I have done over 26K miles in my first year of ownership. The V70 has been a real education as regards driving experience & I constantly find it showing me how poor my driving is & how well the car drives, except on comedy-small bumpy roads when the poor lock & short suspension travel jarrs a bit. But I digress..

26K miles, mostly motorway. One thing I did find noticeable at high motorway speeds was a light feeling at the back end. I go back to my earlier statement that I feel my driving ability is crap, despite having ridden bikes since I was 17 & bikes & cars since I was 21. I'm now 35 & I still consider my skills are poor, thus I did not really trust my judgement with the cars handling. All I did notice after the spoiler was fitted was that at the same speeds as before I was expecting the car to feel the same way as I have been used to for the past year, but it was totally different. It is most noticeable in gusty conditions with undulating road surfaces. It does feel more planted on the road, which you would expect.

Just thought I'd pass-on my experience as I thought it would help others who felt the same. Maybe if I put some weight in the back like the Police do, maybe I wouldn't need downforce on the back!

Gas mileage-wise it's at about 27mpg, which is exactly as it was before. I have had over 30mpg when I was driving for economy, but I've been doing

80-100 on main roads so I can say it has not affected fuel economy noticeably, but I guess Volvo don't fit it when they compile the official mpg figures. They'd be a bit stupid to!

Then it isn't doing anything.

Actually a true spoiler reduces drag by reducing (spoiling) air turbulence.

However, wings on race cars increase drag and decrease gas mileage. If you don't believe me, then watch the Daytona NASCAR race. It is one race where downforce, drag and fuel economy are at all at a premium and the cars are very sensitive to each. They optimize downforce to reduce drag and increase fuel economy. But they are going 180 MPH.

Spoilers reduce turbulence....and downforce increases drag Therefore spoilers improve consumption while downforce worsen consumption (and in this case we see no change in consumption). And following the thread of the argument further, is it not possible that we have a reduction in turbulence improving the economy AND also a small amount of downforce increasing consumption by the same amount??? A reduction in turbulence can also improve stability hence this could be what is being observed.

Just my .02.....

I have a 2004 XC70 and drive the Autoban here in Germany from a 160km to 180km constantly with no spoiler and haven't felt anything abnormal in the rear. Like one said here it keeps the dirt down.

Have too admit it is a great car!!!!

Chuck;

Is that--160-180 KMPH a typical speed in Germany for decent non hot rod cars--just a bit over 100-110 MPH?

Do many people zip along well over 200 KMPH, or is the traffic so thick as to make this imposable?

Here in the east coast USA major roads are around 75-80 MPH--just under 130 KMPH around cities during busy times--NJ Turnpike, Pa Turnpike, Rt 95 etc...

IME you can only really press on at quiet times, early morning, late night etc. During the day the autobahn seems to be more congested than even British motorways. In thin traffic I'd say that there are lots of cars doing 100mph, but the trucks still hold up the job, especially on the narrower autobahns.

The standard of autobahn driving is much higher than in other countries I've driven - I guess it pays to check your mirrors before pulling out when something could be approaching behind at 180mph.

Notwithstanding, on several occasions I've topped 150 mph in Germany. On virtually every occasion there was a 911 or something similar 4 feet from my rear bumper. Clearly there are plenty of places in Germany where you can get the 155mph limiter removed!

Yes, it is a typical speed and at times I am passed or get lights flashes at me to move over so I can be passed.

Chuck

It must be heaven !

Brian East Coast US

To be fair, there isn't much derestricted autobahn left. Most of it seems to be limited (and it's been a while since I was over there so there's probably less now). What remains is very good though!

If you ever saw an accident on the Autobahn you would think differently. In one accident I saw, the entire side of a car was sheared off. You could see the people inside what was left of the car. The car that hit them was wrapped around trees way down the road. I don't know if there were any survivors.