RX8SpdDmn

I weighed my car tonight at work on a 4-wheel in-floor scale. The results were not exactly as expected.
fyi: The readings were in kilograms and read to the nearest 1/2 kg. I then converted the numbers all to lbs.

Basically, it came out that my overall weight (without me in the car) was 2967.5 lbs with a distribution of 52.5% Front and 47.5% Rear. I do NOT have a spare tire. Could Mazda have been quoting a 50/50 weight distribution ONLY if you had the worthless spare tire!?

rotarygod

How much gas was in the car? Typically the measurement is taken with a full tank of gas. What you will find on scales is that each wheel can have very different readings. On some of the RX-7s you would see more than 100 lbs difference just betwen the left and right front wheels.

EDIT: I see now that you were almost full. Those numbers are more balanced than many other cars. Apparently it is a little front heavy.

RotaryManiac

Your b and b midpipe probalby took 10 pounds off the car, not sure how much of that was in the rear. Also you have the appearance package- that might be a factor.

RX8SpdDmn

No, I don't. I just have the wing (in the rear) and the mud flaps (at each wheel).

The B&B Midpipe is in the middle of the car.

BRealistic

http://dictionary.reference.com/search?q=curb%20weight


curb weight
n.

The weight of a fueled automobile with standard equipment but without cargo or passengers.


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I am surprised that your car's weight was 60 lbs under the official curb weight from Mazda for a base 6 speed manual. It makes me wonder if those scales are that accurate- meaning the tenth of a lb read is false precision. Did you try weighing the car revcersed on the scales to see if the weights matched the previous readings?

Moostafa29

I seem to remember someone weighing in around 2880lbs, or something like that. I wanna say it was Xyntax.

zoom44

read the advertising again- it says near 50 50 and the published distribution by several sources has it at 52 48. ask ikewrx he'll tell you real quick

BRealistic

That can't be correct. That's just a 100lbs more than a new Civic EX sedan.

QBallz

I'm pretty sure that is correct for the Base 6spd, but I don't think that was with a full tank of gas.

* 1 gallon of water equals 8.33 lbs.
* 1 gallon of gasoline equals 5.8 to 6.5 lbs.
* 1 gallon of ethanol equals 6.59 lbs.

RX8SpdDmn

Well, I was down a bit of gas. Maybe a little oil, too? I know the scales are good. I've been using them in testing and they were calibrated this year. I work for a major automotive manufacturer, so this isn't a cheapie scale.

The catalytic converter is a very heavy piece. I might have close to a 40lb weight savings there. That definitely would account for the bulk of it.

BRealistic

Cheapie or not- it still needs to be calibrated. We have a $250k saw at the plant that can easily be off by inches and 10 degrees if not calibrated regularly.


Did removing the cat make more power? Just ... I am in an area that does not have ANY vehicle inspections........ But I should not even consider going there...

zoom44

hello??? is this thing on?

RX8SpdDmn

Read my statement again. It was calibrated this year. The thing is not often used and it zeros out with no weight on it, which accounts for something.

Yes, I got a bit more power since I removed the cat (~8hp). More then a cat-back system will give you (2-5hp). It's a lot lighter than the cat, and it shoots flames The fumes are suffocating, though, if you're in an enclosed area. They're just really strong, otherwise.

http://www.scottbarton.net/anthony/M...meThrower!.wmv

Ole Spiff

Well if you figure a gallon of gas is about 6lbs, and you're missing about 2 gallons according to your numbers, and you add the weight of the spare tire and kit in the back, you're probably missing about 50-60 lbs of weight in the back that Mazda would have used to calculate the distribution.

RX8SpdDmn

That's what I'm thinking. I'm just a little upset that it only has 50/50 weight distribution if you have the OPTIONAL spare tire kit and a full tank of gas.

RX8SpdDmn

The curb weight in Mazda's brocure is 3029 lbs for a 6-speed "with popular options", which might make up more of the 60 lb difference. Also, the scale read to the 1/2 kg and I did straight conversions of every number and rounded to the nearest 1/2 lb. So, the numbers are within a pound of actual.

Jaguar_MBA

Relocate the battery to the trunk...that should help some.

zoom44

Nubo

I bet Zoom44 would have some good info

Nubo

The difference between a full and empty gas tank is going to move the CG more than the spare tire kit. And since CG changes with fuel level, it's only natural to measure the "official" CG with a full tank. I guess you could measure without fluids, but wouldn't reflect driving conditions. I'd say 52/48 is pretty close. I guess they weren't quite as maniacal about balance as the original Miata guys; I think I read they actually would hang the car by a hook. Notice where the battery (and *cough* spare tire) ended up in the Miata....

If you think you're noticing a difference, I'd say get the spare. I think it's worth the weight. I never realized it was moving me more towards perfect weight balance, but I'll take it

Get the tire, replace the battery with a big honking Optima AGM in the trunk, and I think you'd have the balance plus increased reliability.

MadDog

I think I've read somewhere that optimal handling is actually had with something a little different than 50/50. Maybe the 52/48 is actually better.

zoom44

its a conspiracy!!!! IGNORE ME AT YOUR PERIL i have my finge ron the button and ill use it!!!!

G8rboy

Zoom who?? I keep hearing these faint mumbles from the basement...

neit_jnf

mazda's advertisement is "near" perfect 50/50 weight distribution in most conditions. Notice how having the driver in the car shifts the weight rearwards.

The weight will shift farther rearwards with 4 people in it, so basically the car stays nearly perfectly balanced regardless of passenger load.

Gord96BRG

Yes, they were almost exactly as maniacal about weight distribution - despite the advertising copy, the original Miata was never 50/50 either. Just ask all the guys who've corner-weighted their cars!