Ive had my GS250 for a few months now and covered 5000 miles. I've only ever filled up with Shell Vpower. I usually have the "after refill" MPG in the 28-29 range by the time I've used a full tank. This is with motorway driving accounting for 10% or so of the mileage.
A few days ago I filed up with a tank of tesco standard unleaded and straight away struggled to get the after refill mpg into the 26's mpg and just managed 27.1 mpg after 15 miles of relaxed motorway driving (65-70 mph). I'll see how it goes but so far the extra expense of Vpower pays for itself with better mpg. Ive never seen such difference between vpower and standard unleaded before including on my IS250.
My last car was a Honda Accord Diesel which was very economical, but displayed 10% less consumption than you could demonstrate from full to full at the diesel pump.
My IS300h which I love is similar. I tested it full to full and it said 54.8mpg, actual mpg was 51.6. I'll do it again and I'll get it's the same.
Have any of you done this?
By Mark c
Hi Guys first time posting on the forum but wanted to share my experience. I have a 07 Is220d for almost a year now with 120k. I drive about 400 mile per week motorway driving.
When I got the car it wasn't great so got it remapped. I then got it carbon cleaned through the air box and put some fuel cleaner in it to and still not great. Low revs poor. Couldn't get 40mpg no matter what I done. Monday night I decided to pull of the egr valve and it was totally blocked. The fuel cleaner and 1 hour carbon clean was useless. I soaked the egr valve in brake cleaner and also the steel pipe. Used a tooth brush to get as much carbon off the manifold. Put it all back together and I'm not getting 50 mpg at 75mph. Takes any gear at low revs. Different car. It took me about 2 hours and it's only 6 nuts.
Hope this helps some of yous.