Mixing fixed with tracker

krockroc

New mortgage will be £180,000 on a £475,000 property.

At the moment I have reserved a 5 years fixed product at 4.49% with Nationwide. Just waiting for approval. It will be £999 per month payment during the 5 year period. I like to play safe.

Option 1: £999 per month

My existing mortgage is £23,210. I was just thinking of leaving the £23,210 on Nationwide's variable rate of +2% (currently 2.5%). This would work out as follows:

Option 2: £974 per month
1. Mortgage £156,790 – 5 year fixed at 4.49% = £870 per month.
2. Mortgage £23,210 – tracker currently at 2.5% = £104 per month.

I know it's only a saving of £25 per month and the base rate would have to rise to 2.5% to make me pay more per month than the fixed rate but something is telling me it's still more beneficial in the long run to have a lower amount on the fixed rate (£156,790 rather than £180,000). I can't get my head around it but was hoping someone here can point it out or just give me an opinion on what's best to do? Maybe there is no advantage but I'd like to know? Hopefully I've made sense?

I don't mind answering questions why I've gone with Nationwide rather than shopping around for the best deal (I know Nationwide aren't the cheapest at the moment). Any comments on Nationwide mortgages are also welcomed.

Cheers in advance.