2008 GS automatic first tank drove 327 miles total of which 33% were highway miles. Highway miles were under 60 mph and all driving was smooth and easy.Air conditioner was on for all driving. I was kind of disappointed that I onlygot 29.48 mpg on this first tank.

Question 1. Is this normal?

Question 2. How many miles on vehicle beforeoptimum MPG can be expected?

 

You realize the automatic GS is rated at 24-mpg city and 33-mpg highway? 29.5-mpg when driving 66%-city and using the A/C is normal.

1. Yes
2. You will get slightly better mileage after the first few thousand miles but don't expect a large increase under similar conditions. Using less A/C and driving more highway will gain the biggest increase. Upper 30's is not out of the question.

 

Thanks NovaResource for the info.

 

My mileage has gone up about 3-4 mpg from new to 5k.