Retroplay

So a little over a week ago, I switch from Speedway gas to Shell V-Power and have noticed that my mpg has been gradually increasing. I haven't had a ton of experience with the affect on the SC yet, but I just drove the IS from Michigan to Florida and used only V-Power the entire way. By the end of my trip, I was reading 38MPG. This was coming from both with the built-in and my T-Mobile SyncUp Drive OBD device. I was getting a range of 340-380 miles on a tank. The longer I drove, the more range it got when filled up. Might be the detergents in the V-power cleaning up the system.

My brother will be driving the SC down here for me in a couple weeks and I am going to ask him to use only Shell V-Power as well to see.

Anyone have any similar experiences?

OBP

Have not tried V power but with just Costco premium, I have obtained a fair mileage readout ( as in not rolling downhill and on a sustained basis over a long road trip ) of about 27 mpg when cruising hwy.

jzdulexus

Gas mileage can also be affected by many factors like tire pressure and outside temperature. The greater the difference between the engine temperature and that of outside air the higher the efficiency of internal combustion engine. So the MPG would be at its best when the engine is hot and outside is cold.

JohnnyCake

You don't seem like a Grandpa driver, so that is really amazing. For a true test, I'd like to see actual miles and actual gallons rather than the computer.

Caflashbob

No miracles occur. The fuel system seems to have been leaned out with the fuel selection IMO

GmanSC

The only complaint that I have for the SC is the mileage. I am used to with the fuel economic car like my wife's Prius and my daily driving Corolla, so driving the SC, it's kinda bother me a bit.
Did you guys notice that the first half of the tank went down quicker than the second half? (by reading the gauge).

Retroplay

The computer in the IS is reading 24MPG now that I have been driving it in the city on rather short trips for the last week. I agree, 38 seems a bit crazy even for the IS.

I'll see if I can get my brother to collect some real data on his trip down with my SC.

And no, I am no grandpa driver, though I mostly behaved myself on this trip sticking around 80 most of the time. Keep in mind that cruising on the highway, there isn't much hard accels, decels, and idling. The car was pretty much in the 6th gear the entire time.

texsexlex

iTrader: (3)

I'm in the neighborhood with OBP, if I usually have a nice trip & stay in the 75-80 cruising range, I can get 27 to readout on the computer also

Retroplay

Your SC is a MY 2006+ if I remember correctly (6 speed)?

Jabberwock

My 2003 SC430 gets pretty low MPG so far compared to the 2006 LS430. Around our small town with lots of stop lights/signs, and 25/30/45 mph limits, we get 18.0 mpg avg. Driving sustained highway speeds the SC 430 gets 24.1 mpg average. My 2006 LS430 averages 21.9 mpg in town and 26.7 on highway in same area and same driving style. Pretty amazing considering how much bigger the LS430 is, but the LS430 does have a 6 speed AT. I drive both cars like an old geeze.

texsexlex

iTrader: (3)

...no mine is a 2002

Harold57

Don't forget that the SC430 weighs about 4000 lbs.

Coleroad

and, if driving with the top down you'll cut gas mileage. So when looking at mileages, you need to know top up or down.

jzdulexus

I have both 2006 LS430 and 2007 SC430. And the difference in mpg is exactly as indicated by the official numbers about 2mpg. So I get about 21mpg on SC and 19mpg on LS.

Jabberwock

I almost always drive with the top down so that clearly decreases mpg. I honestly did not expect much in terms of MPG from my 2004 SC430. I drive it almost every day but don't drive significant miles so overall gas cost is trivial compared to all other related costs. I have always been impressed by the mpg my 2006 LS430 gets given its size, weight and power.