Adjustable but if it's that bad then your clutch is probably near worn out. If you mess with adjustment with a worn clutch, be sure to remember to set it back when you put in a new clutch. Cold weather also will make an engine run like crap due to the poop fuel atomization. which is why takes can have coolant passages in them to help warm the intake faster. cold air intake isn't good at a certain point. it can be too cold. our rigs aren't the best cold runners. they do need a minimum of a minute before you think to move it and if you only take a minute, you better just grannie it for another 5 minutes till that needle starts to lift and don't beat on it till the needle gets at lest past the 1st quarter mark. <img src="/forums/images/graemlins/patriot.gif" alt="" />