What's your ti's fuel economy?
 

E36:er's,

Thought I could start a fuel economy thread. There are threads about this but this is what I thought we could do here. Please, just list the year of your ti, current mileage and odometer reading after the gas tank light comes on. The 318ti fuel tank will hold 52 liters (13.7 US gallons) including 8 liters (2.11 US gallons) in the reserve tank. This comes to 44 liters (11.6 US gallons). Please, do not post mpg stated in online reviews/other forums. Post your true "old school" reading: fill up your tank, reset odometer and when the gas tank light comes on...post your odometer reading.

If you are only doing highway, city or a combination, please state so.

A decent 318ti should make around 28-32 mpg. But this is not what I get. Anyways, here it goes:

Model: 318ti M-Sport
Year: '98
Transmission: Automatic
Tyres: Dunlop Winter Sport M3 225/50ZR16
Mileage: 162 000 km
Odometer Reading (on a full tank until gas tank light came on): 430km (267 miles)
Fuel used: Shell, Regular unleaded
Highway km only

My results translates into;
430 km/44 L = 9.77km/L
267 miles/11.6 gallons = 23.0 mpg

What's your reading?

My understanding the fuel tank was 55L.

Model: Racing Technics 328ti Turbo
Year: 1996
Mileage: ??? km
Fuel used: Caltex 98 RON

I roughly get 100kms per quarter city driving, so it works out to be roughly 13.75L per 100kms. On the highway, I got roughly 150km per quarter, so that worked out to be 9.16L per 100kms.

New ECU just installed should be more efficient with sequential firing and closed loop, so I'll post my new findings after I drive my car around a bit.

1996 Active, Auto.

The OBC says 30-33 mpg depending on how much city driving I do.

1996 Sport, Manual.

I keep track in the "Road Trip LE" app for iPhone. My average over the last 15,879 miles is 27.45 US MPG. That's probably about 50/50 - city/highway.

mine varies quite a lot. i do a ton of city driving. i seem to average around 24mpg. i notice a big difference in consumption when i drive very soft to even a more lightly aggressive fun driving style

I know you want hard numbers.. but I don't have them. I generally take the numbers on the pump and the numbers from the Odo and do some quick math to figure out my mpg.

In mixed city/highway driving.. I get 27 to 28 mpg. About a 50/50 mix of highway and city.. this has been consistant from 90,000 miles up to the cars current 145,000

Highway, I once saw 36mpg during the worst of the gas price spike when I drove from NJ to DC and back and kept it exactly at 65mph with the windows barely cracked, sunroof "popped" at the back and the rear windows propped open. About as close to hypermiling as I get.

Usually it gets around 32mpg on strict highway driving.. but I am not a fast driver. I set the cruise for 70mph and just go.

Mixed driving 70/30 (city/hwy) I usually get 26-28mpg. All hwy is around 32-33mpg. That's with a 5spd and 3.73 rear end. Those numbers are based on the OBC, I do keep track with a spread sheet too.

Edit - Oil is usually Mobil 1 10w-40 on 205/60-15 all seasons.

would be interesting to know what oil and weight each user has in their car as oil weight can have an affect on MPG. Tires/wheels too..

My "lifetime" average over the last several years of recording the mileage at each fill-up is right at 30 mpg. That's a mix of highway, city, autocross, AC, wide summer tires, narrower winter tires, etc. About the only constant has been oil weight at 5w30, but that's been several different brands of synthetic. For the OP, if you're not seeing at least high 20s on the highway then something's wrong.

I am just not a fast driver, never have been. My thing was cornering. If I do not have to slow down, I do not have to accelerate

Diclaimer:
Non hatchback content within, sorry.

Zolf, those numbers are really low.
My 93 325IS with 250,000 miles (origional M50TUB25 engine and Getrag 5 speed) consistently gets 27-28 MPG on the interstate (mixed between the mountains in VA / WV and the boring flat mid west) with mid grade (89 octane) fuel, cruising between 65 and 75 depending on traffic. I use Mobil 1 10W40 oil, and 225-45-R17 Bridgestone potenza Pole Position tires.

I'll report back when I have a ti.

1998
342,000mi (550,000km)
10W-30
Manual

31-32mpg highway (@ 75mph)

To save fuel stick with the OEM rims and tire size. Don't accelerate fast. No AC, keep windows up. Also, consider tire diameter will alter odometer reading. Check your speedo against GPS and determine mileage offset.

I would check things like vacuum lines and maybe even the ICV, I've seen/ heard of those doing really weird unexpected things to performance when they wear out.

That write up does not apply to you. The idle control valve on the M44 is right on the front of the throttle body. You only need to remove a couple of Torx bolts and unplug the harness connector to remove it. This is the thread you want for that:
http://www.318ti.org/forum/showthread.php?t=27697

How old are your o2 sensors? They can be worn out enough to cause mpg problems without turning on the check engine light. You can also change the oils in the transmission and differential to some nice synthetics and see gains, depending on what's in there.

Yeah, general tune-up, fluid changes, and O2 are the first things to go after to improve your mileage.

Also, what kind of fuel do you get? Does it have a high ethanol content? Fuels are mixed considerably different between different countries and even different parts of the same country. I'm surprised people in the US are still seeing over 30mpg with almost all of our fuel being E10 now.

Any suggestions on synthetic lub for the tranny and diff?

I use Red Line for both. MTL in the transmission and the 75W90 in the diff. You can also use their ATF for the manual transmission if you like. The factory fill was ATF. I find that it shifts better with the MTL in it.

mohaughn, good call on the fuel. I forgot about that. You should be using mid-grade and it probably wouldn't hurt to change the filter if it's been a while or you don't know when it was done.

Today, on my way home from work the check engine light came on. Plugged her up and error code was given for maf.

That could definitely be related to your problem.

check realoem.com to get a part number, then there's probably a sticky some where full of the best vendors for tis, but my personal favorites are bavauto, ecstuning, and turner motor sports.

I get 6 MPG

I bought mine used from a member here. Depending on the actual code, it could be a vacuum leak. Heck, mine was a code for adaptive fuel limit, not the actual maf code, but the maf was just a hair out of range and caused all kinds of hell.

Goosejuice, I can only assume you had a hell of a lot of fun when you were getting 6 MPG.

im getting 26 miles to gallon (UK) town driving ranging from stop start to the odd blast up to 60mph. doing 20 miles communte a day

running standard 15" wheels and tyres still

I had the feeling my consumption was higher than it should be. From recollection, and this should be fairly accurate although I always fill up when I reach 1/4 tank, I get about 500-550km, mixture of city and highway, to a full tank or when the gas light would come on.

Two things to note though are my car is 323Ti and when I am on the highway, which is pretty much at some point everyday, I'm on the autobahn... and I won't pretend to be efficient when keeping with the flow often means travelling at 160km/hr.

That being said, I still seem to think my consumption should be better but I think I'll see a change in summer due to weather and tires ect. Also, my car has 125,000km.

Actually no, for 2+ years ive never actually driven my car. It broke when i bought it, pretty awesome first car huh?

Right around 29 MPG avg

25 City 35 Highway... Consistently... at ~70MPH

Running stock size highway radials.

Dave

Trixie's averaging about 27 mpg. I've got a stock engine running stock rims with a 30 mile commute. I hit a lot of bumper-to-bumper traffic, so I guess that isn't too bad. On Christmas weekend I did a lot of highway driving and my mileage crept up to 30.5 mpg, but 26 to 28 mpg seems to be the usual range.

1998 with 172K on the clock. I have a 20-mile commute each way to work and I use back roads with very little other traffic, so no stop-and-go. With over a year's worth of gas purchase data on fueleconomy.gov, the 318ti is averaging just over 31-mpg. Considering the sporty nature of the car, I am very pleased with the fuel consumption.

Just got my MAF sensor shipped in today. I will repost new mpg as soon as I've made the switch. Hopefully it will be an improvement to my current (crappy) 23 mpg.

its not exact.
 

Only had car 2 months but so far. ... computer tells me 30.5.. and up at times. Mostly country roads. Very pleased with the 318ti!

We have been averaging 29.5 with a lot of stop and go traffic on 89 octane.

I change back and forth between 89-93, I think I can tell a little difference. Probably likes 91 the best.

Average highway:31
Average City: 27
driving moderately hard around the city: 21

1999 M-sport, manual.

This is an old post. haha.

1998 manual with 172k miles.

City: about 18
Highway: about 32 - 35

I am all over the place, i know. I average about 22 in state college, PA and about 28 in my hometown.

1996 manual w/ 143k

When I first got the TI, I was doing about 60/40 city/highway and I got 27mpg
Since then it's only been going up. I do about 50/50 now and my last tank was 37 mpg. I drive between 65-80. I love this thing, great mpg and fun. so much better than my old rx7

37mpg at 60mph?

i took mine on a trip to northern georgia last week anad averaged 31 to 36 mpg

I think the gearing plays a big part in the fuel economy here. I'm planning on picking up a 318ti for a winter beater/commuter car and want to play with the ratios a bit.

Consider this:

Automatic 318ti Gear Ratios:

• 1st: 2.86
• 2nd: 1.62
• 3rd: 1.00
• 4th: 0.72
• Diff: 4.44
• 70 MPH RPM: 3318

Manual 318ti Gear Ratios:

• 1st: 4.23
• 2nd: 2.52
• 3rd: 1.66
• 4th: 1.22
• 5th: 1.00
• Diff: 3.45
• 70 MPH RPM: 3074

When comparing ratios between a manual and an auto here, you basically "skip" 1st gear in the automatic trans but you have overdrive in 4th gear. It makes up for the gearing differences with the very tall 4.44 diff.

So what if we have an automatic 318ti and swap out the stock 4.44 diff for the manual 3.45 diff? 70 MPH RPM drops to 2389 RPM. That could make some serious differences in gas mileage as long as the car can handle the lower effective torque output. If not, I can try a 3.73 or 3.91 ratio to not drop the gearing as much. Performance would obviously suffer, but that's what I have the other build for.

Has anyone experimented with this?

25 city, 36 highway. Just started useing 100% gas no ethanol so interested to see if any improvement. Will post once i know