JJH

iTrader: (1)

I have an 07 type-S with 136k miles. Since I purchased the car in February I have done a few minor modifications that I believe have lowered the gas mileage little slice by little slice. Here's what I have done:

-Switched to 5w-30 Red Line full synthetic oil
-Switched to all Red Line type-F ATF
-Switched stock tires (235/45-17) to 255/40-17.
-Switched the air filter to a K&N air filter (regret doing this)

After doing a 1200 mile road trip to the outer banks coming from up north and doing nearly ALL highway driving at ~65mph, I think it's safe to say that the minor modifications that I have done have decreased my MPG. I only averaged 29mpg on the way down. Same with the way back after resetting the MPG counter to see if I could do better. I had a trunk full of luggage and a passenger and put Shell V-power in my car the entire trip.

Tire pressure was checked in the morning in the garage and blown up at the same time to ensure that cold tire pressure was at 35psi front and 32psi rear. Same was done on the way home.

shenrie

well the wider tires arent helping gas miliage, but it seems like the rest of it would be enough to offset. what kind of miliage were you getting prior to these mods? changed your plugs recently?

wont ride as nice, especially with a 40 series, but for road trips I need more miliage on I bump up the pressures to 40f & 35r.

justnspace

iTrader: (1)

Full trunk eh?

truonghthe

^^^lol.

justnspace

iTrader: (1)

^i'm dead serious.

about how much weight did you have in the trunk?

parasitius

Had the weirdest trip this weekend...

Ohio->NYC. Got 30 MPG going up but struggled to get 26~27MPG (back and forth on the gauge) coming back. The only difference was that I brought back 2 chocolate bars ($8/ea in NYC) and I took an empty camera, but came back with the memory chip loaded with 1000+ photos (maybe make it weigh a bit more from all the electrons)

Generally I've not seen a variation greater than 1MPG for long trips - typically I get 28~29. No mods of any sort to the car.

Jackass

I will bet the tires are the biggest culprit. I lost 3-5mpg just on tires and I didn't put wider tires on, just switched from the OE Grand Touring tires to UHP All-Seasons.

BrownBuck

am i missing something here? 29 isn't bad? lol and especially with a FULLL CAR....i wanna know what OP normally got...and if he normally had a FULL car

JJH

iTrader: (1)

Have a look at this post:

https://acurazine.com/forums/showpos...1&postcount=83


As for the plugs, I'm not really sure when they were changed. I need to call the dealership that the car was serviced and check and see if they did them when they changed the timing belt and serpentine belt.

As for the luggage weight, if I had to guess I would say that there was close to 100lbs of weight if that.

The tires that I had on the car before were bridgestone blizzaks and I would get north of 30mpg easily. I purposely tried to drive with MPGs in mind on this vacation and road trip and the best I could get was what I got.

Undying Dreams

iTrader: (3)

Tires and fully loaded trunk + another passenger.

ez12a

yep. Some say the rule of thumb is every 100 lbs is another 1 mpg lost. You already lost at least 2 with just luggage and the passenger.

that and the wider tires aren't helping.

BrownBuck

Man if i sniffed 30 i would be happy...i don't drive that aggressive and the best i can get is 26ish....i usually even out and sit at 25 high+city...so if i do ALL highway i can imagine getting 30ish...altho i've yet to go on a trip and confirm that.

What do you avg city+highway usually?

justnspace

iTrader: (1)

MPG is directly related to average MPH.
check your MID

LoveMyTL-S

How much does the passenger weigh? I'm with the group here, weight + wider tires = less MPG.

94eg!

You installed thicker oil, thicker atf, wider tires and an oil-soaked air-filter and your wondering why your mpgs went down? If MPG's were such a major concern, you probably should not have done ANY of that.

I noticed an instant 1-2 mpg loss in my daily commute going from M1 5w20 to M1 0w30. I went from 29 every tank to 27 every tank. I know most say you won't see any difference between different oil viscosity, but this sure was an odd coincidence.

BrownBuck

huh? don't understand why ur talking about that?

My MPG for City is around 17-20 and Highway is around 27...and i avg usually(majority highway driving) 25 on the dot...SOMETIMES 26 if i drive more freeway...i've never tried to drive the whole tank on the freeway yet so i don't know what my legit highway mpg is according to the MID.

aBe 024

I think what BrownBuck is trying to say is that on the MID, the higher the MPH you average the higher your MPG will be.

twigglius

iTrader: (6)

Aided and unaided by Wind. It's like track and field yo.

swoosh

iTrader: (5)

Yes Redline 5w-30 will yield a little less (marginally) as it is a very thick oil...almost as thick as other brands 5w-40....i used to run 5w30 from Mobil 1 but when i switched to mobil 1 i went with 5w20 (first fill was 5w30 and recently switched to 5w20)....

the ATF shud affect your gas mileage....weight affects MPG....

i am fully bolted in and i used to get 33MPG highway....when i got my exhaust my MPG went out the window....started getting 29-30MPG highway....with weight loss i went back upto 32-33MPG....

you should also check the elevation....i used to drive from KC to STL and get higher gas mileage when i drove TO STL as STL is at a lower elevation as compared to KC....

PS: I always traveled with a passenger who weighs 115 lbs and some stuff....and i always get 30+ MPG highway

Bearcat94

This.



You may think I'm kidding, but I'm not.

OH --> NYC is more downhill and more likely with the wind than the return trip. Changes in temp can be a factor as well.




Edit:

FWIW, I get ~30-ish highway MPG in my '07 TL-S. Without 'excess' weight in the car.

JBONN

Elevation of Youngstown Ohio = 850ft
Elevation of New York City = 186ft

...I be you could have gotten even better mileage if you used Mexican overdrive!

DeathMetal

iTrader: (2)

Conservation of mass negates this possibility.

LaCostaRacer

Did you check what the EPA estimate is for your car? It happens to be 26 MPG highway and you're exceeding that already. I would say you're getting a consistent performance with a 3.5L engine. I get 31 with a smaller engine and skinnier tires so you're about right. I would add more pressure to the rear tires too. I'm running 36 all around with some Michelin Pilot AS/Pluses and the handling is great and I got an improvement in mileage because I use to be at 29 like you before.

DeathMetal

iTrader: (2)

Isn't this just effectively over-inflating and removing contact patch, creating an artificially skinnier tire?

Jackass

I always noted just the opposite...although I attribute the difference in 91 octane on the trip to STL and 93 going home. These days I usually try to stop in Columbia for fuel since that is the furthest West 93 octane goes on I-70 in MO for the most part.

YeuEmMaiMai

+1 for wider tires as they increase rolling resistance. I drive a 02 CL-S and I get 29-31mpg at 72mph. Any mod that lets the engine breathe easier will by default affect gas milage as you need more fuel to go with that air.....

LaCostaRacer

It appears to make no difference in the contact patch at all- at least visibly. I did this based on a tip from a google search because my outside rear edges are wearing more. I noticed improved handling (wet & dry), a slowdown in wear, and improved MPGh.

Every tire is going to be different which is why I gave my tire info. Those Pilot A/S Plus tires seem to wear much faster in the back on the TL. There's a rumor that this was one of the reasons Costco stopped selling them- I haven't checked but notice they're not in the Carlsbad warehouse the last time I checked. I'll be getting Continentals my next time.

truonghthe

extra weight doesn't help out with the gas mileage.

I hate cars

Any mpg loss has nothing to do with the fluids used. Its weight and tires coupled with the fact that unless you do a round trip calculation its meaningless. Weight of tires, rolling resistance and a very real aerodynamic penalty are causing this. Redline has significantly less friction from the zddp and moly along with the base oil and better ring seal which overrides any immeasurable mpg penalty from the heavier weight. Oil weight is just a small part of the picture and once warm theres a very slight difference in weight.

ZOMGVTEK

This was taken after I got home.



I started off in Columbus, OH with 3/4 tank of unknown fuel, all tires around 34psi, what appears to be fairly old cheap Valvoline oil, a single passenger and nothing else. A/C was set to Lo most of the time, fan speed 1, radio/headlights on the whole way. 55-65MPH highway speeds, limited traffic prior/after that. This was with a 07 6MT Type-S, almost entirely stock, no drafting.

It looks like its settled on 24-26 now with lots of short trips and traffic.