I recognise that accursed route - the M8. Damn you useless road...
I don't go west of Harthill often but I have for the past couple of months - to East Renfrew and to Argyll & Bute and various other western 'colonies'
. Normally most of my trips are either north on the M9, south to Newcastle on the A1 or A68 or south to Eng-el-and on the M8-M74. These are longer journeys and I'll tap about them at the end.
Going east from Glasgow the worst initial part is the M8 in Glasgow itself from the Kingston bridge until The Fort. It is mostly flat but it usually has a lot of traffic. That isn't too bad as the traffic tends to move slowly. Once past the turn off for Carlisle the M8 climbs to Eurocentral which is more or less full of traffic and solidly uphill for about 5-6 miles. The road then climbs more gently to Harthill and then dips for about 5-10 miles and then dips and rises until it reaches Livingston and eventually on to Embra.
Despite it being a motorway it is only 2 lanes each side, every other motorway South of the central belt is 3 lanes each side. Grrr.
My method is to crawl until the Fort. If I leave a large enough gap I can P&G with the G bit being 3-4 times the P bit because of the speed here. Once I get to The Fort then everyone else wants to be in the outside because of trucks joining from the M77 link, but I'm happy because they do my speed (roughly 60-ish) up the long climb. After that I do aggressive P&G with an average speed of 65 (P&G between 70 and 60) and longer coasts on the downhill parts.
Monitoring my MPG I can do East->West, Embra to Glasgow (M8 roundabout to the Kingston bridge) averaging 60 on my SG2, 56 on the onboard. Going back I can do 58 before 3pm, nearer 50-ish after then when the Bridge starts to back up.
As for going south I can do Embra via the M8 and M77 to just south of Birmingham and back on a single tank these days whereas before I could just about make it to Knutsford on the way back before needing fuel.
On my last fast trip south though I was bored and in a hurry. Just at Carlisle a guy in a Bentley Continental GT passed me at a very high speed so I set my cruise to follow him about half a mile behind and did the last leg quite quickly.
Sometimes I kind of think a Polo Bluemotion would be good, or even a C1 Diesel. And then sometimes...
