# If you filled your tires with helium would it make your car lighter? **URL:** \ **Category:** Factual Questions\ **Created:** [October 28, 2008, 2:53pm UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942 "2008-10-28T14:53:58Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![furryman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/furryman/32/99_2.png) [@furryman](https://boards.straightdope.com/u/furryman)\ **Post date:** [October 28, 2008, 2:53pm UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/1 "2008-10-28T14:53:58Z")
If you filled your tires with helium would it make your car lighter? Is it even possible? If so why don’t they do it? ---
**Author:** ![pkbites](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pkbites/32/204_2.png) [@pkbites](https://boards.straightdope.com/u/pkbites)\ **Post date:** [October 28, 2008, 3:04pm UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/2 "2008-10-28T15:04:40Z")
I think the helium atoms are too small to work in standard tires. Your tires would go flat pretty quick because the helium would seep out. Just like what happens to a balloon. ---
**Author:** ![Chez\_Guevara](https://avatars.discourse-cdn.com/v4/letter/c/aeb1de/32.png) [@Chez\_Guevara](https://boards.straightdope.com/u/Chez_Guevara)\ **Post date:** [October 28, 2008, 3:06pm UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/3 "2008-10-28T15:06:00Z")
No, but your SatNav voice directions might be a bit squeaky. ---
**Author:** ![pkbites](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pkbites/32/204_2.png) [@pkbites](https://boards.straightdope.com/u/pkbites)\ **Post date:** [October 28, 2008, 3:11pm UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/4 "2008-10-28T15:11:10Z")
Didn’t Mythbusters try this with a football? I believe the weight difference would be so negligible that it wouldn’t be worth your time or expense trying to keep your tires inflated. ---
**Author:** ![Santo\_Rugger](https://avatars.discourse-cdn.com/v4/letter/s/e95f7d/32.png) [@Santo\_Rugger](https://boards.straightdope.com/u/Santo_Rugger)\ **Post date:** [October 28, 2008, 3:39pm UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/5 "2008-10-28T15:39:37Z")
> [@pkbites](#): > > Didn’t Mythbusters try this with a football? I believe the weight difference would be so negligible that it wouldn’t be worth your time or expense trying to keep your tires inflated. This. For a conservative back of the envelope, tires are inflated to 3 atm. Assuming, again for conservatism, each tire is three foot diameter and one foot wide with no rim, each tire is 7 cubic feet. 28 cubic feet is basically a cubed meter, and a cubed meter of air has a mass of about 1kg. So, even with these ridiculously conservative numbers, being able to somehow fill your tires with a complete vacuum would save less weight than, say, 1/2 a gallon of gas or having the driver and passenger riding with an empty stomach. ---
**Author:** ![Philster](https://avatars.discourse-cdn.com/v4/letter/p/13edae/32.png) [@Philster](https://boards.straightdope.com/u/Philster)\ **Post date:** [October 28, 2008, 3:51pm UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/6 "2008-10-28T15:51:20Z")
Related article, as the Master Speaks of using lighter-than-air gases in tires: > **[Is it better to fill your tires with nitrogen instead of air?](https://www.straightdope.com/21343817/is-it-better-to-fill-your-tires-with-nitrogen-instead-of-air)** ---
**Author:** ![zut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zut/32/2875_2.png) [@zut](https://boards.straightdope.com/u/zut)\ **Post date:** [October 28, 2008, 4:29pm UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/7 "2008-10-28T16:29:51Z")
> [@pkbites](#): > > I think the helium atoms are too small to work in standard tires. Your tires would go flat pretty quick because the helium would seep out. Just like what happens to a balloon. I looked this up a while ago. For natural rubber, permeation rates are 4.8X10[sup]12[/sup] molecules/(sec_cm_atm) for O[sub]2[/sub], 1.75X10[sup]12[/sup] molecules/(sec_cm_atm) for N[sub]2[/sub], and 6.3X10[sup]12[/sup] molecules/(sec_cm_atm) for He. So leakage should be roughly 3:1 worse with helium v. air. That’s not \*horribly \*worse, but it’s probably _noticeably_ worse. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 28, 2008, 6:44pm UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/8 "2008-10-28T18:44:01Z")
> [@](#): > > This. For a conservative back of the envelope, tires are inflated to 3 atm. Assuming, again for conservatism, each tire is three foot diameter and one foot wide with no rim, each tire is 7 cubic feet. 28 cubic feet is basically a cubed meter, and a cubed meter of air has a mass of about 1kg. So, even with these ridiculously conservative numbers, being able to somehow fill your tires with a complete vacuum would save less weight than, say, 1/2 a gallon of gas or having the driver and passenger riding with an empty stomach. Right: It’s important to remember that helium doesn’t have any inherent lifting properties; it just doesn’t have all of the weight that air does. So whenever you’re thinking about replacing air with helium somewhere, the question is, how much does that air weigh? And the answer to that is almost always “precious little”. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [October 28, 2008, 9:25pm UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/9 "2008-10-28T21:25:48Z")
This sure doesn’t save much. Why not urinate before driving? It would save way more weight, and also improve your chances of survival if you get into a bad accident - one of the more common “internal injuries” victims die of is the extravisation of urine into the abdomen from a ruptured bladder. ---
**Author:** ![Keeve](https://avatars.discourse-cdn.com/v4/letter/k/f07891/32.png) [@Keeve](https://boards.straightdope.com/u/Keeve)\ **Post date:** [October 28, 2008, 10:30pm UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/10 "2008-10-28T22:30:24Z")
What **Chronos** said. ---
**Author:** ![audient](https://avatars.discourse-cdn.com/v4/letter/a/ad7895/32.png) [@audient](https://boards.straightdope.com/u/audient)\ **Post date:** [October 29, 2008, 1:02am UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/11 "2008-10-29T01:02:11Z")
one nit - weight saved from wheels gives more bang for the buck. Rolling weight has more of an effect on mileage than the non-rolling weight in the car. I don’t know by what factor. But I still agree it would be negligible. ---
**Author:** ![Drum\_God](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drum_god/32/44_2.png) [@Drum\_God](https://boards.straightdope.com/u/Drum_God)\ **Post date:** [October 29, 2008, 1:07am UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/12 "2008-10-29T01:07:52Z")
> [@Napier](#): > > This sure doesn’t save much. Why not urinate before driving? It would save way more weight, and also improve your chances of survival if you get into a bad accident - one of the more common “internal injuries” victims die of is the extravisation of urine into the abdomen from a ruptured bladder. Oh great. :rolleyes: Now one more thing to obsess about. “C’mon kids. Go before we leave. If we’re in an accident, you don’t want extravisation of urine into your abdomen.” ---
**Author:** ![J\_Cubed](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@J\_Cubed](https://boards.straightdope.com/u/J_Cubed)\ **Post date:** [October 29, 2008, 2:23am UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/13 "2008-10-29T02:23:53Z")
I think people overestimate the awesome power of helium because of how floaty balloons are. But if you think about it, a balloon filled with air is not that heavy to begin with… ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 29, 2008, 3:25am UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/14 "2008-10-29T03:25:39Z")
> [@](#): > > Rolling weight has more of an effect on mileage than the non-rolling weight in the car. I don’t know by what factor. But I still agree it would be negligible. Good catch, but at most, it’s a factor of 2 difference (for weight right on the rim of the wheel). ---
**Author:** ![furryman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/furryman/32/99_2.png) [@furryman](https://boards.straightdope.com/u/furryman)\ **Post date:** [October 29, 2008, 5:11pm UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/15 "2008-10-29T17:11:49Z")
> [@Chez\_Guevara](#): > > No, but your SatNav voice directions might be a bit squeaky. [SatNav] Follow the yellow brick road. [/SatNav] ---
**Author:** ![Hampshire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hampshire/32/4887_2.png) [@Hampshire](https://boards.straightdope.com/u/Hampshire)\ **Post date:** [October 29, 2008, 6:03pm UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/16 "2008-10-29T18:03:42Z")
> [@J\_Cubed](#): > > I think people overestimate the awesome power of helium because of how floaty balloons are. But if you think about it, a balloon filled with air is not that heavy to begin with… Similarily if you filled the entire back of your car with helium filled balloons (a much larger volume than that of your tires) would you expect it to make your car significantly lighter? ---
**Author:** ![Santo\_Rugger](https://avatars.discourse-cdn.com/v4/letter/s/e95f7d/32.png) [@Santo\_Rugger](https://boards.straightdope.com/u/Santo_Rugger)\ **Post date:** [October 29, 2008, 6:52pm UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/17 "2008-10-29T18:52:27Z")
> [@Hampshire](#): > > Similarily if you filled the entire back of your car with helium filled balloons (a much larger volume than that of your tires) would you expect it to make your car significantly lighter? No. All you’re doing is displacing the air, which will be at one atmosphere. Even if you’re displacing 12 cubic meters, that’s still only going to be about 10 kg savings (assuming 12 cubic meters of He has a mass of 2 kg). Think about how big a hot air balloon is with respect to the gondola and passengers to get an idea of how much volume you’d need to have an appreciable difference. > [@Chronos](#): > > Good catch, but at most, it’s a factor of 2 difference (for weight right on the rim of the wheel). Which is still basically .1% of the weight of the rest of the car, if that. ---
**Author:** ![BwanaBob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bwanabob/32/2985_2.png) [@BwanaBob](https://boards.straightdope.com/u/BwanaBob)\ **Post date:** [October 29, 2008, 8:55pm UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/18 "2008-10-29T20:55:07Z")
> [@Napier](#): > > This sure doesn’t save much. Why not urinate before driving? It would save way more weight, and also improve your chances of survival if you get into a bad accident - one of the more common “internal injuries” victims die of is the extravisation of urine into the abdomen from a ruptured bladder. Ouch! I’m never going to drive home from work with a full bladder again. ---
**Author:** ![CC](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@CC](https://boards.straightdope.com/u/CC)\ **Post date:** [October 29, 2008, 10:06pm UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/19 "2008-10-29T22:06:51Z")
> [@Philster](#): > > Related article, as the Master Speaks of using lighter-than-air gases in tires: > > [Is it better to fill your tires with nitrogen instead of air? - The Straight Dope](http://www.straightdope.com/columns/read/2694/is-it-better-to-fill-your-tires-with-nitrogen-instead-of-air) Whoa - I just checked that article out and found this strange statement by Himself: “More important, nitrogen doesn’t support combustion, which is one reason aircraft and the space shuttle use nitrogen in their tires. The wisdom of this precaution was brought home by the crash of Mexicana Airlines flight 940 on March 31, 1986. Shortly after the Boeing 727 took off from Mexico City en route to Puerto Vallarta, an overheated landing-gear brake caused a tire improperly filled with air instead of nitrogen to overheat as well and explode, rupturing fuel and hydraulic lines.” This has NOTHING to do with combustion. This has to do with thermal expansion - at least the way He explains it. Both air or pure nitrogen would have behaved the same way. The explosion may have ruptured lines because of the force, but there’s no reason to think that any part of that disaster should be traced to the presence of some oxygen in the tires. ---
**Author:** ![r4ge](https://avatars.discourse-cdn.com/v4/letter/r/e5b9ba/32.png) [@r4ge](https://boards.straightdope.com/u/r4ge)\ **Post date:** [August 31, 2015, 3:23pm UTC](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942/20 "2015-08-31T15:23:47Z")
I realise I’m late haha Just wanted to chime in and mention that wheels are unsprung weight so they are definitely worth pulling weight off of. 2lb of each tire is alot more beneficial than 8lb off anything above the springs. I’m not sure if the innerliner can hold helium but I do know this, if it can’t then you probably won’t find many tires that can. Most tires are made using the same type or innerliner. It would probably be a cool thing to try but you’d do better to get lighter rims and smaller tires for weight reduction/performance increase. > **[Unsprung mass](https://en.m.wikipedia.org/wiki/Unsprung_mass)** > > The unsprung mass (colloquially unsprung weight) of a vehicle is the mass of the suspension, wheels or tracks (as applicable), and other components directly connected to them. This contrasts with the sprung mass (or weight) supported by the suspension, which includes the body and other components within or attached to it. Components of the unsprung mass include the wheel axles, wheel bearings, wheel hubs, tires, and a portion of the weight of driveshafts, springs, shock absorbers, and suspensio... [Next page](https://boards.straightdope.com/t/if-you-filled-your-tires-with-helium-would-it-make-your-car-lighter/469942.md?page=2)