Tire and rim weights

[California98Civic]

Originally Posted by BabyDiesel

... and that is the only other thing that changed.

I am

I don't think you know that wheel choice is the only thing that changed, and there is a very good probability that, although the wheels are not helping city driving, other things have also changed. Imperceptible changes in your throttling, wind patterns, routes, average daily temps, humidity, the number of stoplights you hit during the tank, minutes idling, and perhaps most importantly... the possibility of a creeping mechanical issue reducing economy but not yet setting off a CEL. I have dealt with that last one kinda often this year. Grrr.

But in the end, I agree the greater wheel weight will hurt city driving fuel economy and must be a contributor here.

Sorry

[BabyDiesel]

Originally Posted by RPM

Tire manufacturers specify a recommended rim width range for each tire size. A 185/70 R14 tire typically requires a minimum rim width of 5". In this case, 4" wheels are a liability and something I personally wouldn't consider. I can image how poor the handling must be. It's interesting that the coasting distance decreased. Thanks for sharing that info!

My loss is everyone else's gain with regards to information

The handling has decreased slightly, not enough to get in an uproar about. I can't wait to get the other wheels back on, as I rediscovered that a Honda Insight's stock wheels are 14x5.5"... and they run the skinny Potenzas

Originally Posted by California98Civic

I don't think you know that wheel choice is the only thing that changed, and there is a very good probability that, although the wheels are not helping city driving, other things have also changed. Imperceptible changes in your throttling, wind patterns, routes, average daily temps, humidity, the number of stoplights you hit during the tank, minutes idling, and perhaps most importantly... the possibility of a creeping mechanical issue reducing economy but not yet setting off a CEL. I have dealt with that last one kinda often this year. Grrr.

But in the end, I agree the greater wheel weight will hurt city driving fuel economy and must be a contributor here.

Sorry

As much as I hate to admit it, you are right California98Civic. There are too many variables to know exactly what is causing my mpg decrease. All I know is the coasting distance is down and tire temperatures are up. I'm glad that I do not do much city driving! Stoplights and stop signs are painful as always.

[California98Civic]

Originally Posted by BabyDiesel

My loss is everyone else's gain with regards to information

The handling has decreased slightly, not enough to get in an uproar about. I can't wait to get the other wheels back on, as I rediscovered that a Honda Insight's stock wheels are 14x5.5"... and they run the skinny Potenzas



As much as I hate to admit it, you are right California98Civic. There are too many variables to know exactly what is causing my mpg decrease. All I know is the coasting distance is down and tire temperatures are up. I'm glad that I do not do much city driving! Stoplights and stop signs are painful as always.

And I think some of the comments about the 5.5 tire on the 4.0 rim are really important. I hadn't notice that before writing to you. That sounds unsafe, tempting sidewall failure. I guess that's why the higher temps. Yikes. Glad you are removing them. Also glad you posted honestly about the difficulties. People learn that way--and not just you but others of us too.

[BabyDiesel]

It was worth a shot IMO. I see many people running 12.50" wide tires on 7" rims around here with no issues! 5.5" on a 4" rim didn't seem that bad in comparison.

Honesty is my policy, and I try to provide the data and reasoning for what happens in my situations. I know guest view our site quite a bit as well, so this will dissuade them from going down this path along with members.

I have to figure out what I am going to do with 4 14x4 space savers with no spare tires now...

[2000mc]

Before you go switching back, I thought one of the reasons for the space saver wheels was making space, the offset making wheel skirts easier to do. Are the wheels set in farther with the space savers? If so, enough to effect wheel skirt design? if they are set in deeper in the fender, I think that would harm your aero if not running skirts front and rear

[BabyDiesel]

Originally Posted by 2000mc

Before you go switching back, I thought one of the reasons for the space saver wheels was making space, the offset making wheel skirts easier to do. Are the wheels set in farther with the space savers? If so, enough to effect wheel skirt design? if they are set in deeper in the fender, I think that would harm your aero if not running skirts front and rear

I looked through my old pictures and the space savings are minimal. It is along the lines of 1/2" farther into the fender, if that! So the front covers can be slightly more flush than with the 14x5.5s. I'd rather have a small redesign of my skirts and less Crr!

It may also be the tires that is making the rims have little effect. With the space saver wheel & tire, the inset of the combo was much greater compared to the MX-3/185 combo and the spare/185 combo.

Here is pictures of the different wheels with the same tires:

[Chrysler kid]

Mount the spare wheels backwards for the deep dish wheel look!

The side walls don't look over flexed to me, however their foot print stays the same or can even get larger on a smaller width wheel.


I would also weigh the pros and cons of duct taping cheap stuff everywhere on your car. Getting sex from females often out weights the benefit of duct tape aero mods, if I recall you are in college and you should be getting laid by now

If you're already married I say step it up and do the whole car in duct tape, kind of like a vynl wrap

[BabyDiesel]

No sex for me! I'm remaining chaste until marriage and the duct tape and coroplast does a good job of keeping it that way I haven't always been this way, but it is important for me and my girlfriend/soon-to-be fiance

On with the rims: I do believe I am going to switch back to the MX3 wheels. I have until the 19th of June to return the spares to the JY and get my $60 back. The moment came when my brother ordered new 15x10s for his truck and they weighed 21 pounds! These 14x4s weight 16ish! The others were around 12! Nope, I want my lightness back. The RE92s will be just fine on them anyways since stock Insight wheels were 5.5 inches wide too. I'll post updates when it happens. Probably Wednesday.

Is there anyway to check tire footprints? Is love to compare my rims and see if there is any differences between the tire footprint.

[niky]

Originally Posted by BabyDiesel

Is there anyway to check tire footprints? Is love to compare my rims and see if there is any differences between the tire footprint.

Inkpad. A4 paper. Muscles.

[BabyDiesel]

I'm not going to get a chance to compare footprints as the space savers went back to the junkyard where they belong today! I put my MX3 wheels back on, which are 3-4 pounds lighter and 1.5" wider. All I can say is WOW! Coasting, DWL and acceleration are all improved noticeably and my mpgs are going up.

I plan on doing a second round of coast-down testing to see if there has been any reduction in rolling drag and aero drag.