Non scientific: How driving style affected my 2.5s MPG!

rookie · #1 (**permalink**) 08-20-2005, 09:07 PM

Well it seems like fuel efficiency is more and more talked about so I wanted to see how the "driving style" that is mentioned often affects MPG. It is not really scientific, see what I did and found out, no fancy measurments were done

First - understand my commute: 24 miles each way. I drive my car to work and back only (child car seats are in wife's car so during weekends - Alti rests). I take the same route pretty much always with slight variations to avoid accidents etc. It is about 50:50 Hwy:City drive, I hit many red lights every day.

1st test tank: I hammered the car like I never do. That was the tank with some fuel injector detergent cleaner in there too so I figured I'd stomp on it and clean injectors out

. Almost every start was aggressive, red lined (5-6K RPM) in 2nd and 3rd gear multiple times in a day. I never spin my tires, but they did chirp multiple times that tank. Hvy cruising at 80 mph in 5th gear. Final number, after measuring at the pump - 27.8 MPG. I was surprised to say at least, I expected 26 or lower???

2nd test tank: This was my "usual" driving style, as I usually drive. I accelerate as I see fit but not crazy, try to anticipate the lights ahead. Shift point is 3K RPM, but I get it up to 5K a few times. Cruise on hwy at 3K RPM. Final number, after measuring at the pump - 29.3 MPG. This is what I usually get so no surprise there.

3rd test tank: This was more "conservative" than I usually drive and it took some doing. I moved the shift point to 2.5K RPM (was hard as I shift by sound). I mean lotsa shifting. At 50 mph I'd already be in 5th gear. No crazy starts and not a single redline (got it to 5K once though). Hwy cruising at 2.5 K RPM. Final number, after measuring at the pump - 30.2 MPG.

Few more facts about the car:

I refuel when the light comes on or just before that, so I usually drive about 450-470 miles on a tank. The car has about 38,000 miles on the clock. Mobile 1 synthetic 5w-30 oil, 7.5 K drain intervals, Shell gas only (their cheapest stuff - and the reason I use that only is because for some reason - it gives me 30-40 miles more / tank than other stuff). Tires at 35 PSI, front and back. AC on 100% of the time during the above testing. Manual transmission, as you probably figured out

There you go - for what's it worth, I never really tested this "driving style" theory before, it's interesting to see how it works out!

ManInCamo · #2 (**permalink**) 08-20-2005, 10:31 PM

sure beats my 15.3 mpg on my new '05 SE...

ca04alti · #3 (**permalink**) 08-20-2005, 11:43 PM

the only time i have ever come close to 500 miles to a tank was a very long ass drive to vegas.

Control Altima Delete · #4 (**permalink**) 08-21-2005, 12:54 AM

What is this "fuel injector detergent cleaner" and what made you put that in?

rookie · #5 (**permalink**) 08-21-2005, 02:53 AM

Quote:

Originally Posted by Control Altima Delete

What is this "fuel injector detergent cleaner" and what made you put that in?

STP makes several fuel injector cleaners. Some made with alcohol, some with "jet fuel" and some just add detergent to the gas (like Shell V-Power gas is supposedly high on).

I run a bottle of fuel injector cleaner even oil change (7.5K miles), the whole bottle, on the full tank. First time I did it at 20K and my MPG went up from 26 to 29 where it is still today (when I drive normally). Seeing I use cheapest gas, it does not have the additive package that the higher octane has so I figured - I might as well help clean my injectors!

Ah - one more thing I wanted to say - in my experience, the difference between synthetic and non synthetic in MPG is very noticable. Meaning - running synthetic gives me 40 miles / tank more than dino of the same oil weight. The reason I know I am not making it up is that during a precat recall, stealership changed my oil without telling me and they reverted me back to dino. I wondered for few weeks what the heck happened with my MPG and I blamed it on new tires I got right around that time. However, then I realized what happened, changed the dino out at 5K for Mobil 1 synthetic and my MPG went back up. Yay for M1!

Adam West · #6 (**permalink**) 08-22-2005, 08:45 PM

Chevron Technron Fuel System Cleaner

'nuff said

hrbib21 · #7 (**permalink**) 08-23-2005, 05:35 AM

If you're going to spend money on additives, why not just buy premium that already has detergents? You could buy a tank or two of that and end up with the same effect. I don't think it's wrong to use additives, though. I used injector cleaner on all my previous vehicles.

I've said it before and I'll say it again: Driving style has more to do with what MPG you get than anything else. Example: a guy on one of the Explorer forums I belong to started a thread a while back about his attempt to get 30mpg out of his Explorer. After some mods and a total change in driving style, he's there.

rookie · #8 (**permalink**) 08-23-2005, 05:42 AM

Quote:

Originally Posted by hrbib21

If you're going to spend money on additives, why not just buy premium that already has detergents? You could buy a tank or two of that and end up with the same effect. I don't think it's wrong to use additives, though. I used injector cleaner on all my previous vehicles.

I've said it before and I'll say it again: Driving style has more to do with what MPG you get than anything else. Example: a guy on one of the Explorer forums I belong to started a thread a while back about his attempt to get 30mpg out of his Explorer. After some mods and a total change in driving style, he's there.

You know - I wondered before: if you use 2 tanks of premium (more additives) - would that be equivalent to using a bottle of fuel injector cleaner?

I guess we'd have to know how much additives the gas has eh...