98 ES300 Poor gas mileage?
Hi guys. I'm usually found in the LS forums, but am here to help my Dad get his gas mileage better with his 98 ES300
The car does run well and has been well maintained, 150,000kms roughly.
It gets around 20mpg with gentle highway driving which makes it more thirsty than my LS400. Other than the poor gas mileage, the only thing the car does wrong is a high idle when its cold, higher than what i consider a normal cold idle, it's over 2000rpm. I would expect around 1200-1500 to be normal on cold start.
Any ideas? I'm thinking something along the lines of coolant temp sensor, maybe o2 sensors? Is there a common fault i should be looking for?
Thanks for any input guys