Ditch spare tire to reduce weight and save gas?

[Joe1]

My Subaru has a full size spare. I was thinking of ditching the spare to reduce weight and theoretically increase MPG's... What increase (if any) in fuel economy would I realize by removing a 23lb tire and steel rim (don't know the weight of the rim).

I realize it would be a real PITA if I got a flat far from home w/o a spare.

 

[ToyotaNSaturn]

this would only be worthwhile if you like to chances and are very thin. I could lose some weight myself, but if we lose weight from our bodies, it would effectively be the same thing....

I'd rather be safe than sorry...keep the tire in there...

 

[Steve S]

I would hope you're kidding ! You would never be able to prove the savings.

 

[TylerL]

Here is how you really reduce weight to save gas and go faster. Link It may hurt resale value though.

 

[Audi Junkie]

I play it safe and carry 2 spares, you never know. Yeah, I am reasonable, I cut back from carrying three. Just kidding. I actually put my doughnut on the back outboard of the CRV, which already was running an undersize as a spare. Some vehicle with an outboard spare could do ok with just a spare delete, but this one needs something on the back for aesthetics.

This mounted-outboard spare delete/modify situation seems to be the one instance you could see mpg gains. I already have front end aero mods installed and make the EPA 25mpg hwy.

 

[bdcardinal]

i took the spare out of my mustang. however i changed the front brakes to a brembo setup, so my spare would not clear the calipers.

 

[byez]

I heard that some Porsches don't come with spares and just a can of fix-a-flat for weight reduction.

Personally I carry a spare & a nail repair kit. I don't like being stranded.

 

[rpn453]

If the total weight of the spare, jack, and wrench is 60 lb and the car, with typical load of passengers, cargo, and fuel, is about 3500 lb, and assuming that rolling resistance and unrecoverable kinetic energy account for 50% of the power consumption, you're looking at about 0.85%. This is a pretty crude off the top of my head analysis, but I think it's good enough to assume that you'd probably save somewhere between 0.5% and 1% on your fuel costs.

 

[Kestas]

Volvo analyzed their truck fleet and found that 0W- weight oil saves almost 1% in fuel savings when compared with 15W- oil. If your analysis of 0.85% savings is true, then I think removing a spare merits at least as much discussion as using 0W- oil for fuel savings.

 

[Lorenzo]

The difference in fuel consumption from 23 pound weight savings would be completely insignificant. Focus on things that have real impact: driving smoothly, lower your speed and acceleration, keep proper tire inflation and avoid unnecessary trips. That's about all you can do.

 

[mrsilv04]

You would probably do just as good by never running with a full tank of gas, and only carrying a maximum of a half tank.

 

[Virtuoso]

Boss's wife just bought a new van..it didn't come with a spare tire. It was eqipped it with run-flats instead. Wonder how long it will be before many cars on the road come this way? Or how many already do?

 

[Drew99GT]

Some new cars come with a can of tire inflater/sealant instead of a spare.

 

[WishIhadatruck]

Originally Posted By: Drew99GT
Some new cars come with a can of tire inflater/sealant instead of a spare.


I see GM is making spare tires optional on a lot of their cars now. For a car company it is useful to gain the .2mpg or whatever it works out to be because they have a CAFE they need to meet. For the individual it might not be worth it if. A flat tire would be a real pain. I make a focused effort to improve mpg but I'm not about to remove my spare tire. I have considered running my fuel tank below 1/2 however but haven't ever tried it.

 

[Bamaro]

Dont forget the extra weight that your car is lugging around that can be found under your belt.

 

[y_p_w]

Originally Posted By: Virtuoso
Boss's wife just bought a new van..it didn't come with a spare tire. It was eqipped it with run-flats instead. Wonder how long it will be before many cars on the road come this way? Or how many already do?

Run-flats may not necessarily result in fuel economy savings - not that you claimed so. Depending on the setup, they could be made with thicker sidewalls or require an insert. Unsprung weight from the tire and/or insert could be detrimental to performance and/or fuel economy. In any case, using a modern run-flat generally requires the use of a pressure monitoring system. The original Mini started using run-flats back in the 70's (don't think there was remote pressure monitoring). The current BMW-era Minis have run-flats and no spares. Their tires are also way too big for the car. I hear the 17" versions actually detract from the performance.

In any case, I thought that remote tire pressure monitoring has a phased in requirement for US sold cars.

 

[Harley Anderson]

You guys suggesting fix a flat, what happens when you lose a valve stem? I think I'll ditch my spare and keep one of my motorcycles loaded incase I get a flat. Gas prices are high but man I wouldn't be without my spare or a couple hundred pounds of tools in the back of my truck, no matter what prices go to.

 

[y_p_w]

Originally Posted By: Harley Anderson
You guys suggesting fix a flat, what happens when you lose a valve stem? I think I'll ditch my spare and keep one of my motorcycles loaded incase I get a flat. Gas prices are high but man I wouldn't be without my spare or a couple hundred pounds of tools in the back of my truck, no matter what prices go to.

I know someone with a Lotus Elise. The original Elise has run-flats I think, but he got an aftermarket package without run-flats for extra performance. He keeps a couple of cans of Fix-A-Flat and carries a AAA card and a cell phone. In a worst-case scenario I guess he insists on a flat-bed tow.

 

[XS650]

Run flats also cost a lot more for the same level of tire performance and life, are noiser and harsher riding.

I live with them on my Corvette because there is no room to carry a removed wheel/tire, even if you do use a donut spare.

You also can't depend on a cell phone working unless you always drive on boring roads. People who always drive where cell phones work have my sympathy.

 

[y_p_w]

Originally Posted By: XS650
Run flats also cost a lot more for the same level of tire performance and life, are noiser and harsher riding.

I live with them on my Corvette because there is no room to carry a removed wheel/tire, even if you do use a donut spare.

You also can't depend on a cell phone working unless you always drive on boring roads. People who always drive where cell phones work have my sympathy.

I don't think my coworker with the Elise takes it around where there won't be cell phone coverage. He believes the fix-a-flat has himself covered pretty well.