Driving on a spare tire

Yes, if you will read your Owner's Manual it will recommend that in the event of a flat front tire, to move a rear tire to the front and put the smaller spare on the rear. The car is heavier in the front.

Also, the spare tire is only meant to go a short distance at low speeds until you can get the full size tire repaired. The small tire is not meant to be a long term tire.

 

You want to avoid driving on a spare with any car, especially a front tire on a FWD car. The issue is that the spare is smaller than the regular tires which means that the spare will spin faster than the tire on the other side causing potential issues with the car's differential. That is why most owners manuals have a warning that tells you to limit the number of miles driven and the speed - I have not checked mine, but I would imagine that the warning is in there. If you are going to drive more than just a short way on the spare I'd recommend moving the spare to the back of the car - not great, but better.

 

What they said......

The potential differential problem is that the spider gears (*) will be in continuous operation instead of just on corners and they aren't made for continuous duty.

I think that problem is overstated, unless you have a limited slip differential which a Prius doesn't. That said, you don't want to find out if that problem is overstated or not, so keep your speed down to 55 or so, which you should do because of the crapy donut anyway. You can also ease the wear on the spider gears by driving gently without a lot of throttle.


(*) Yes, that's a real technical term for those gears.

 

If you feel the need to confirm the excellent advice given:

http://www.toyota.com/t3Portal/document/om/OM47685U/pdf/sec_05_02.pdf
Starting on PDF page 27, manual page 532 to PDF page 40, manual page 545

 

yes as they say you wanna move good tire from rear and put donut back. It is also a good idea to swap front/rear on other side good luck

 

What would be more dangerous if you had a flat on the front?

1. trying to rotate your tires along side the road to get the temp spare on the back using the jack and lug wrench provided? or

2. put the thing on the front and drive slowly to the nearest place where you can get your tire fixed?

I think if the compact spare is properly inflated (to 60 psi) it will easily carry the weight of 1/2 the front of the car (which will be less than 1000 lbs) and at 50 mph or less will get you to a tire shop with no problems. The compact spare size is selected to be an approximate match with the normal tires so the slight difference in circumference will not matter to the differential at the speed and distance you will be going.

 

I think the issue is that because you have different sized tires, you are in a constant turn as far as the differential is concerned. You will generate a lot of heat and wear turning left (or right) for 50 miles.

In the rear, the tires are not connected to each other and can 'turn' freely.

So, if you need to get 7 blocks to a tire store, mismatching the fronts is not bad, but if the distance ends in 'miles' I would put it on the rear.

Off topic, I have some long curves in my route, anyone notice getting better mileage in curves than going straight?

 

Love you guys! I got my first flat (2006 Prius - not a bad run) on the passenger front wheel. OMG. Driving home was a nightmare: I couldn't figure out why the car would kick in some limiter at 25mph...I could barely get my car up to 35mph. The low-air-pressure light stayed on and the VSC light would flicker on at about 25mph. Heaven forbid if I took my foot off the accelerator or-- worse-- even tapped the brake. The Prius would no longer maintain a speed (let alone accelerate); the gas pedal essentially stopped working. Only pulling over to the side and coming to a stop-- then accelerating again-- could I get my speed back above thirty. I wasn't speeding or trying to drive fast (I've always been cautious with compact spares)-- I was just trying to maintain city street speeds. AGH!

I managed to limp home and found...THIS! Thank you so much! I just finished switching out the compact spare with the rear tire. Hopefully this will help me get to Costco tomorrow morning with fewer problems. Again-- thanks everyone!

 

^^^
Was the spare tire way low on air? I'm not surprised the low pressure light stayed on, the flat tire is still flat. I'm not sure if the spare itself has a sensor.

I had to go ~145 miles on the donut spare but luckily, it was the rear passenger side tire that was damaged and that's where the spare went. I was coming home from a road trip from Vegas and the flat was in the middle of nowhere on I-5 (near Coalinga). The car was totally drivable w/that spare back there. IIRC, I had to inflate the spare as it was very low.

And yes, the low pressure light was on the whole time. Got me a bit concerned that if I got another flat, I wouldn't receive a warning.

 

The spare doesn't have a sensor.

 

Most rear-drive "differentials" that I've seen do not support the spider gears in anti-friction (roller or needle) bearings. The hardened spider gear simply rides on a hardened steel shaft. I would also question how well this type of "plain" bearing would perform under continuous operation. I don't know specifics of the Prius differential.

 

The first time I came across one of theses "emergency" spare wheels was in a hire car (front wheel drive Chrysler Voyager minivan) on a US holiday in 1993 and the car manual stated that the emergency spare must only be used on the rear axle. I was under the impression this was the case in all vehicles with these donut spare wheels and have always put them on the rear. Also the pressure is something like 60 PSI in these things to aid stability and boy does it make a difference when it's not up to pressure. I've driven Mk3 & Mk4 Ford Mondeos with one of these on the rear and with the correct pressure in and under normal driving conditions (i.e. not pushing the speed or handling) I could not feel the difference and there were no flashing TC or ESP lights. I haven't had the pleasure yet in the Prius (touch wood) but I believe the Prius stability control is more sensitive than the Fords.

 

I'm running on spare now

What should be 73mpg commute is now 58mpg, 4 miles.

 

I'd agree with @tumbleweed on this. There's nothing in the Owner's Manual about the temp spare needing to be at the rear. It does caution to keep the speed down, and get the regular wheel/tire on asap, but that's all.

The temp spare has the same outside diameter as the regular tire.

(Guess it's thread resurrection morning for me, oh well...)

 

Ha! I rolled on a temp spare today myself. Also had the flat on the front passenger side. Swapped the rear to the front, placed the temp spare on the rear. Regardless of what that manual says, I've seen way too many transmissions cooked with people running those temp spares on the front getting towed into the dealership. Better safe than sorry. My commute was only 25 miles, but as was said earlier, if your commute ends in "miles", put the temp spare on the rear. Ended up finding what looked like part of an old rusty nail in the tire.

btw - doesn't the sound the temp spare makes remind you of the noise your bicycle tires made when you was a kid going down a hill really fast?

 

Why would temp spare cook transmission? It is the same OD.

 

Yikes, how did that front to back switch for the spare go? Was it on a busy road? It was my rear driver side tire, lucky it was at an apartment complex so it was flat w/no cars going by.

Fastest I drove was 50 mph so missed out on that

It wasn't safe enough to patch it up.it would have save me moula. Ordered an exact model make of it from walmart, yes walmart because it was the cheapest to be here by Friday. Hopefully they can put the new tire on the rim and give it to me to install myself to save money.

 

No issues for me either - in my sons driveway when I changed it. We had it swapped out in about 10 minutes I'd guess. As for a new tire, I was lucky and didn't need it. Nor did it cost me any cash to fix (other than a few bucks I threw at my son to buy a few candybars out of the machine at work) He's a Master Tech at the Honda dealership here in town. Generally gets all of our stuff pretty cheap.

Well maybe I didn't get off cheap. He had me do two pulls in his V6 Turbo'd Civic. I only pulled 12lbs of boost, but my word that car is so fast it scares me. This was the 3rd time - hopefully I won't have to do it much more. It's putting 692hp at the wheels on the dyno - with ONLY 12lbs of boost. Insane...!

Yes scares the crap out of me.

 

No, it's not. I rolled it up to the tire and it wasn't even close.