42mpg, I'm Shocked!

[Rodders_UK]

My GS gets around 24mpg, mostly motorway driving

[maneesh]

I suspect that the GS300 has shorter gearing than the LS versions. I've read about this somewhere on the US forums. This factor plus the aerodynamics of the LS would go some way to explaining "bigger, faster car but same fuel economy"..

[maneesh]

LS has much more of a freewheeling effect, i.e. car would not lose speed very quickly even after taking foot off gas. No real engine braking provided naturally when lifting off gas into a corner. The GS does seem to have some engine braking, and doesn't have the same freewheeling effect.

[marcus wright]

Best I ever had with an older model GS300 was 28mpg cruising circa 90 long distance on French autoroute. Typical driving town (75%), A roads (20%) and motorway (5%) with my last mark 2 GS300 gave circa 20mpg, about the same as the new model GS430 I now have. When we used to drive longer distances with town (25%), A roads (50%) and motorway (25%) we got 25mpg in my first mark 2 GS300, same with the mark 1. All measured via my own calculation rather than the on-board computer.

I would hypothesise that round town driving delivers 20mpg V6 or V8, with a greater distance between the two (in the V6 favour) when travelling longer distance.

Best regards,

Marcus.

[boombang]

My dad has a GS430 and averages 32MPG on long runs. Does dip to low 20's around town.

I managed to get it a lot lower when I drove it over xmas - but boy was it fun.

[Matthew_McNally]

My dad has a GS430 and averages 32MPG on long runs.  Does dip to low 20's around town.

I managed to get it a lot lower when I drove it over xmas - but boy was it fun.

←

how does he manage that?

I've never seen above 30

[boombang]

Just checked trip comp and last 75 miles since refuelling have been around town - 20.7 mpg

Could be a variety of things:

tyre selection

tyre pressure selection

innaccuracies of onboard trip computer

speed he drives at

the driving techniques he uses.

I know for a fact the tyres are changed every 12-15k (lease car), he checks pressure every journey, he drives usually at 75MPH, leaves very big gaps between cars infront to avoid braking etc.

Using similar techniques I have acheived over 53 MPG in a Peugeot 106 Gti, and in the same car I have managed a whole 9 MPG (not great for a 1.6 900kg car).

My current weekend toy (Peugeot 205 Cti) ranges from 15MPG on a light thrashing to 40MPG driven carefully at 70MPH.

I would say technique and a well maintained car in evey way can gain you / lose you 10MPG or more. (not saying you or anyone drives badly or doesn't take care of the car!).

[willber g]

After picking up the car, filled up with Super Unleaded, settled into an easy 65mph drive on the M4 with cruise control set.

Filled up at other end (just wanted to see what it was like), and found I'd got 42mpg. I had to recalculate 3 times to make sure.

Maybe the lowered Sport suspension makes the car have less drag at speed?

Absolutely shocked, but in a good way!

After picking up the car, filled up with Super Unleaded, settled into an easy 65mph drive on the M4 with cruise control set.

Filled up at other end (just wanted to see what it was like), and found I'd got 42mpg. I had to recalculate 3 times to make sure.

Maybe the lowered Sport suspension makes the car have less drag at speed?

Absolutely shocked, but in a good way!

After picking up the car, filled up with Super Unleaded, settled into an easy 65mph drive on the M4 with cruise control set.

Filled up at other end (just wanted to see what it was like), and found I'd got 42mpg. I had to recalculate 3 times to make sure.

Maybe the lowered Sport suspension makes the car have less drag at speed?

Absolutely shocked, but in a good way!

Is OK to use Super Unleaded in my Mk2 300? If so what are the benefits (or otherwise...)?

Cheers,

Willber