Would the spare be OK for a 220 mile journey

[urmm]

Im at my in laws 220 miles away and have just discovered that one of my front tyres are gone. A quick look at the mobile tyre fitters and they wont cover the bank holiday weekend and i need to be home in time for work. My spare is practically new but is 215/55 16 and my others are 235/40 18. According to a rolling radius calc The rolling radii is almost the same 313 vs 312 mm while the rolling circumference is 1961 vs 1968 mm. Any opinions

Cheers in advance

[urmm]

Gone as in flat with a great socking nail in it. I really doubt you can save it

[urmm]

Car is rwd and the spare is on the front, when you say take it easy, is 65-70mph OK

[urmm]

Thanks for the replies. Just to say that the spare is on and it is the same overall diameter as the other tyres (the tyre not the rim therefore the rolling radius is the same). The only difference is the width (215mm vs 235mm - 2 cm). The AA man said it was OK said if i take it easy (The jack broke while i was changing the tyres - dont worry the car didnt crush me or fall down it was just the handle)

I could try to see if tyre centres are open but I have a horrid feeling they wont have the tyre I want and I dont want to be stuck with a different make of tyre compared to the others, particularly of the same axle (I take that seriously)

Edited by urmm on Saturday 1st January 19:44