D24TIC Cannot get engine warmed up

[Laney760]

I believe due to the following two factors as it has only been occuring for the last 6 days, I cannot get my engine warmed up on my normal town runs. Since bringing the antifreeze ratio up to scratch in the water and with the advent of this colder weather, on my weekday drives of max 8 miles my engine does not warm up as she used to after about 4 miles and I am now doing all these short runs cold, I shouldn't think it's any good for my engine. I'm not just going by my temp guage, which is accurate, she warms up on longer runs at the weekend but the engine feels tight and almost labouring even with higher revs and she is clearly cold and probably oil pressure not up. I doubt there's anything I can do about this but just in case anyone has an answer. I know it's good the antifreeze is doing it's coolant job properly but I don't ever overheat with my head problem and all these short runs cold are doing my car no good I'm sure? Obviously can't run in the winter without antifreeze