Ls430 Fuel Usage In Winter

[curiousB]

I know this has been covered a million times but here’s a current snapshot. Just did a 530 mile one day trip in January weather in IL/IA. Temperatures fluctuated between 8-18 degrees over the day.

Speeds were between 66-79 MPH.

Was a back and forth trip so 264 miles one way and then return on same route.

Running with regular fuel (87 octane) (haven’t used premium in 2 years). I achieved 22.9 MPG for the trip.

Exact details are: 527.7 miles travelled, started with full fuel tank, two fillings along the way 12.029 (midway) and 10.97 gallons (end). Midway filling was with 89 octane (midgrade) as it is cheaper in Iowa than regular. Since it was only a half tank fill up then average is probably 88 octane in the tank for return segment.

So given cold temperature and fighting a mild crosswind all day I feel that is pretty decent mileage for such a large vehicle.

[LS 0181158]

Hmm...your car has a 22.5-gallon tank just like my '98 LS 400, and EPA rating is 18/25 vs. 19/25 for my car.

I've never driven in temps quite as low as 8 degrees, but my average mpg to date over two plus years (obviously mixed driving) is 22.5. I use 93 octane religiously.

That said, my FURTHEST DISTANCE covered on a single tank was 583 miles in August 2008, and my gas mileage for the tank broke down to 27.8 mpg--astonishing for a V-8, and well above the LS 400's EPA highway rating. I averaged 55 mph [per trip computer] over the course of the tank--first easy driving on Vermont's back roads, then a 75-80 mph run down to the eventual refueling stop in Scranton, PA. I filled back up with 20.964 gallons, meaning I still had over 1.5 gallons left--so technically I could have exceeded 600 miles before the car ran out of gas! Of course, I didn't want to go through that in rural mountainous Pennsylvania...

On long highway trips starting with a full tank, the trip computer normally reports a "Tank Average" of perhaps 24-26 mpg--and in my experience it calculates a bit less than 1 mpg high. Efficiency seems to increase noticeably after the car's been run at a steady engine/road speed, well after the engine reaches normal operating temperature.

Not to take anything away from your journey, but why don't you try switching back to premium gas and see if you notice an improvement? I also installed a K&N air filter, although that was after the 583-mile trip referenced above.

By the way, how do you like your LS 430? I think the exterior style is frumpier than the LS 460 and even the LS 400, which is kind of a turn-off, but the interior is WAY more opulent than the LS 400 and even the Mercedes S-Class of 2000-2006. Plus I'm sure the LS 430 continues to be worlds more reliable than any other big luxury sedan! When I'm done with my car, I'm thinking about buying a 2004-2006 LS (like the mid-cycle refresh better with its sharper headlights, LED tail lights and 6-speed auto).

[curiousB]

Not to take anything away from your journey, but why don't you try switching back to premium gas and see if you notice an improvement? I also installed a K&N air filter, although that was after the 583-mile trip referenced above.

By the way, how do you like your LS 430?

I did run premium for the first few years I owned it. Just got tired of the premium gas penalty when no apparent performance benefit. I won't rehash prior posts but even oil company experts have been quoted as dismissive of the need for premium fuel. Anyway I'm happy with the mileage as I wasn't making any attempt to drive in a manager MPG optimum. I just wanted to get home ASAP.

I like my LS430. I have had owned it since Dec '03. No real problems since owning it. Two sets of tires, a couple brake jobs, many oil changes. Did have a passenger side mirror change and an axle height sensor go but in grand scheme of things the total cost of ownership has been good so far.

[LS 0181158]

That is really reassuring. During the time you've had your LS 430, I've owned five used cars (two of them for just a few months several years ago as they were of the sub-$2K variety!). Then I got my LS 400, and it has been by far the most reliable and one of the most pleasant cars I've owned. Like you said, just oil changes, plus two 60K-type services, new brakes and tires (1x), and a $2,400 timing belt/water pump service that included one of the complete 60Ks and replacement of the starter. That's been the car's history with me 115K to 178K, and still driving beautifully with no surprises.

I've considered eventually replacing it with a 2003-2006 S500 or CL500 instead of the logical LS 430 choice, but those late-model Mercedes seem to be maintenance horrors compared to the staid but ultra-reliable LS. And the LS 430 interior is so much warmer. Of course, the LS 460 combines the sleekness and class of the previous Mercedes models with expected Toyota durability, but $50K for a 2007 is still too rich for me! Looks like I'll have to keep my car for a few more years...

Do you have the air suspension option on your car? (I noticed the "axle height sensor"). If so, was that standard on the Ultra Luxury package? I've read to stay away from air suspension cars due to the excessive cost of parts replacement (and that of course goes for the AIRMATIC Mercedes models too).