Actually using the spare tire - 986 Forum

99Roadster · 10-27-2019, 03:21 PM

I have a couple of questions I would like answered if possible.

First concerning using the spare tire...I currently have Pirelli tires on my P-car
Front: 225/40R18 Diameter - 25.1
Rear: 265/35R18 Diameter - 25.3
Spare tire: 105/95R17 Diameter - 24.9

So if I have a flat tire on a rear tire is it ok to use the spare or is the diameter difference going to screw with my tiptronic transmission ?....I seen someone say something about taking off the rear tire then taking off a front tire and putting it on the rear then put the spare on the front.

And I run NGK plugs in everything I own and I want to convert my 99 base 2.5L over to NGK's....So can someone confirm that it would be a NGK BKR6EK (2288) ?

Starter986 · 10-28-2019, 04:36 AM

Quote:

Originally Posted by 99Roadster

I have a couple of questions I would like answered if possible.

First concerning using the spare tire...I currently have Pirelli tires on my P-car
Front: 225/40R18 Diameter - 25.1
Rear: 265/35R18 Diameter - 25.3
Spare tire: 105/95R17 Diameter - 24.9

So if I have a flat tire on a rear tire is it ok to use the spare or is the diameter difference going to screw with my tiptronic transmission ?....I seen someone say something about taking off the rear tire then taking off a front tire and putting it on the rear then put the spare on the front.

And I run NGK plugs in everything I own and I want to convert my 99 base 2.5L over to NGK's....So can someone confirm that it would be a NGK BKR6EK (2288) ?

For how long will you be driving on the spare, regardless of where it is installed? You might consider driving it to the nearest tire repair shop, and as quickly as possible. You might also consider examining your tires at least once a week. An ounce of prevention is worth a pound of cure.

Is everything you own a domestic? Maybe consider just running OEM plugs. Our cars aren't Hondas.

What oil do you recommend? Have you had your IMS replaced? What brand tires are you running?

tonythetiger · 10-28-2019, 10:12 AM

bigger problem, change your tire to spare...where do you put the original wheel? wont fit in truck or frunk or passenger seat. rather then leave the wheel on the side of the road, I got a flat a couple of years ago and had the car towed.
what do others do?

kk2002s · 10-28-2019, 10:31 AM

I fit 2 front tires in the passenger seat.
I would be scared to death to ride on my now 17 years old doughnut spare but if I had to. I also have a can of fix-a-flat

Starter986 · 10-28-2019, 10:32 AM

Quote:

Originally Posted by tonythetiger

bigger problem, change your tire to spare...where do you put the original wheel? wont fit in truck or frunk or passenger seat. rather then leave the wheel on the side of the road, I got a flat a couple of years ago and had the car towed.
what do others do?

I didn't know it wouldn't fit... hmmm.

I removed my spare to rid of the weight... and have the large can of fix a flat and a Slime compressor. Maybe I should renew the AAA membership.

tonythetiger · 10-28-2019, 10:48 AM

Quote:

Originally Posted by Starter986

I didn't know it wouldn't fit... hmmm.

I removed my spare to rid of the weight... and have the large can of fix a flat and a Slime compressor. Maybe I should renew the AAA membership.

HAH! I did the same thing, can of fix a flat and a compressor in the frunk...but still have the spare for no good reason.

BYprodriver · 10-28-2019, 11:19 AM

Quote:

Originally Posted by 99Roadster

I have a couple of questions I would like answered if possible.

First concerning using the spare tire...I currently have Pirelli tires on my P-car
Front: 225/40R18 Diameter - 25.1
Rear: 265/35R18 Diameter - 25.3
Spare tire: 105/95R17 Diameter - 24.9

So if I have a flat tire on a rear tire is it ok to use the spare or is the diameter difference going to screw with my tiptronic transmission ?....I seen someone say something about taking off the rear tire then taking off a front tire and putting it on the rear then put the spare on the front.

And I run NGK plugs in everything I own and I want to convert my 99 base 2.5L over to NGK's....So can someone confirm that it would be a NGK BKR6EK (2288) ?

No issue with the diameter difference, as with any tire adequate air pressure to support the load is critical. Make sure you have 60 psi in the spare, as long as you have that & don't exceed the capabilities of the spare you can drive indefinetly with it. Naturally handling & top speed will be reduced especially with the spare on the rear, so rotating the spare to the front helps drivability. I have driven a Oldsmobile about 350 miles in the heat of summer on a space saver with 4 people & trunk full of luggage.

As Josey Wales said : "A mans got to know his limitations"

lkchris · 10-30-2019, 01:03 PM

The spare tire plus wheel is the same diameter as any Boxster standard wheel/tire specification. Doesn't matter if you have 16, 17, or 18 in wheels.

If you've mounted non oe-spec tires or wheels+tires, you will have a diameter problem and you might hope your flat is a front tire, as of course it's a problem to have different diameter wheel/tires on an axle with differential.

Yes, nice to carry a big bag to put your flat tire in to keep the dirt off your upholstery or girlfriend.

thstone · 11-03-2019, 05:18 PM

Did someone ask about the safety of driving on an old spare?

I got a right rear flat recently on my 1979 911SC in the middle of farm country in Central California. I put on the 40 year old compact spare, inflated it properly, and drove 6 miles (only 6 miles!) on the freeway at 55mph to a tire shop. The full size tire won't fit in the frunk so I put it on a towel in the passenger seat.

This is what it looked like when the tire shop took the spare off - the tread had separated.

There is no provision for a full size spare in this 911 so I bought an unused 40 year old compact replacement spare and simply hope for the best if I ever need to use it in the future.

Your mileage may vary.

BYprodriver · 11-04-2019, 07:10 AM

Quote:

Originally Posted by thstone

Did someone ask about the safety of driving on an old spare?

I got a right rear flat recently on my 1979 911SC in the middle of farm country in Central California. I put on the 40 year old compact spare, inflated it properly, and drove 6 miles (only 6 miles!) on the freeway at 55mph to a tire shop. The full size tire won't fit in the frunk so I put it on a towel in the passenger seat.

This is what it looked like when the tire shop took the spare off - the tread had separated.

There is no provision for a full size spare in this 911 so I bought an unused 40 year old compact replacement spare and simply hope for the best if I ever need to use it in the future.

Your mileage may vary.

I never cared for that design spare, folding the tire is not a good idea.

jaykay · 11-04-2019, 10:11 AM

Egad friends!

....can one recommend the best flat repair compressor / sealant kit to carry in ones vehicle?

I just blew up my portable 12V using it for years to air up tires....it was an Airman with sealant small enough to carry

Oddly enough I was just about to get a slime kit from amazon as they seem to be highly rated.