With all the posts relating to Tyre Pressure and Fuel Consumption, I thought it might be an idea to combine the two.
Since I purchased my MK4 EX in April 21, I have always run my tyre pressures at around 31psi Front and 30psi Rear, I guess in the interest of slightly improved comfort
My best fuel consumption on my usual test run, from Solihull to Stratford-on-Avon via the A3400 (about 16 miles each way) has been around 84 Mpg going out and 65 Mpg on return. Its uphill coming back and the road is subject to 50 Mph speed limit with sections of 30 and 40 Mph.
So, following the post on Tyre pressures, decided to increase the pressures up to the recommended level ie 35psi Front 33psi Rear. and the attached picture shows the results achieved:-
As you can see there is a significant difference in fuel consumption, (93.2Mpg Going out & 70.3Mpg Return) even allowing for errors in the 'Fibometer' which in my view are only in the region of 2, or perhaps 3 Mpg and to me, unimportant. There is a very slight difference in comfort, on poor surfaced roads, but I can live with that.
I don't believe there was any significant difference in traffic conditions, or my style of driving.
I would be interested to see if others have found such differences.