Optimal speed/rpm for gas mileage in 2019 Type R?

[rainytimeronno]

Title says it all.

Now don’t get me wrong, I didn’t get this car for the gas mileage. I’m still going to have my fun. Plus, 80% of my driving is city so my best tanks have been 20-21mpg. My average is sub-20 but I’m only 1300 miles in.

When I’m just cruising, I’d like to maximize MPG. Sometimes I like to make a game of it but I haven’t been able to pinpoint the best ranges yet. The bar in the dash has a little too much latency for me to know I’m doing the best I can be.

Is it better to accelerate under 2,000rpm? Or a little higher? The lower seems like the obvious answer but I came from an 04 Si and I think I recall hearing it’s actually better to be close to 3-4k. That could have been incorrect or the newer technology could perform differently.

Anyways, let me know your experiences! What’s your best tank? What contributed?

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[samji]

I think as long as you don't bog the engine, you can shift lower. I usually shift between 1500-2500 depending on whether or not I'm merging, overtaking, or going up an incline, I never go over quarter throttle (when just commuting), and downshift if I hear any sort of engine bog. I'm in stop and go traffic most of the time and I average anywhere between 23-25. If I'm on the highway mainly with light traffic, I get around 28-30.

I average about 290-320 a tank (haven't had the car that long yet). Only filled up about 3 times thus far. On my way back up to Norcal from Socal, I was able to get about 340 miles but I was well into the reserve tank at that point.

Spirited mountain driving can drain my tank pretty quick though.

 

[TypeSiR]

Shift at around 2500 rpm. 6th gear cruising on the highway. But it’ll be a bit boring driving like this all the time.

 

[Front Runner]

Do you drive/accelerate hard? I drive in the city a lot also but my mixed hwy/city driving average is 28 mpg.

 

[tinyman392]

Do you drive/accelerate hard? I drive in the city a lot also but my mixed hwy/city driving average is 28 mpg.

Is this according to the car's infotainment or measured manually? I've found that the car's infotainment overestimates my gas mileage by about 1.5 MPG.

 

[Front Runner]

Hand calculated from tank to tank. Not computer mpg. Yes computer mpgs are off slightly.

 

[TonyD]

Strangely the best MPGs occur at light cruising ~50 mph in 4-5th gear. I had this happen when I took a business trip to see a customer an hour away along a single lane double yellow type road with a stop light every 5-10 miles. The computer indicated 32mpg.

On my normal 50/50 highway/city commute to work I normally see 28 indicated. (I know the computer is always 2mpg high)

Even on a pure highway trip it will sometimes settle on 30. I guess the air drag at 70 must be enough to make the 6th gear cruising lower than 4th gear cruising.

 

[samji]

Strangely the best MPGs occur at light cruising ~50 mph in 4-5th gear. I had this happen when I took a business trip to see a customer an hour away along a single lane double yellow type road with a stop light every 5-10 miles. The computer indicated 32mpg.

On my normal 50/50 highway/city commute to work I normally see 28 indicated. (I know the computer is always 2mpg high)

Even on a pure highway trip it will sometimes settle on 30. I guess the air drag at 70 must be enough to make the 6th gear cruising lower than 4th gear cruising.

I cruise at 65-70 on 6th gear and managed to get 32.1mpg on a purely highway trip. Why don't you cruise at 50 on 6th gear? Air drag aside, you would be cruising at a lower RPM, albeit you probably will have to downshift before accelerating but I don't get why you have to cruise on 5th gear for going 50mph? Am I missing something here? (genuine question)

 

[willskiGT]

Optimum speed/gear for best MPG would be between 45-55mph in 6th gear.

You can still achieve 29-30 MPG at around 80mph if it isn't too hilly and you can maintain a consistent speed (no slowing/speeding up for overtaking).

 

[Deleted member 31314]

whats fuel economy....? doesn't sound fun lol

 

[tinyman392]

Strangely the best MPGs occur at light cruising ~50 mph in 4-5th gear. I had this happen when I took a business trip to see a customer an hour away along a single lane double yellow type road with a stop light every 5-10 miles. The computer indicated 32mpg.

On my normal 50/50 highway/city commute to work I normally see 28 indicated. (I know the computer is always 2mpg high)

Even on a pure highway trip it will sometimes settle on 30. I guess the air drag at 70 must be enough to make the 6th gear cruising lower than 4th gear cruising.

Drive through rural areas at 55-60 in 6th gear (90% of the drive), suburbs 50 in 6th gear (8% of the time), and neighborhoods <30-35 in 5th gear (2% of the time) netted me about 33-34 MPG on the computer. My computer is about 1.5 MPG off.

Edit: if I go on a multi-hundred dollar road trip going 75-80 I can eventually get the MPG up to the same area.

 

[Deadly Nancy]

The lower the rpm, regardless of speed, the better the mileage is. Simple as that.

 

[TonyD]

.... I don't get why you have to cruise on 5th gear for going 50mph? Am I missing something here? (genuine question)

Sure, to clarify.... its a real road with hills and valleys, stop lights, shopping areas and stretches of open road. Of course you can putter along in 6th in certain places on flat or downhill sections. Some places are more like 35 so you end up in 4th.

It was odd that I wasn't hypermiling or trying at all. It just showed a crazy high MPG for that trip. It wasn't a steady cruise, I was in and out of gears, up and down hills etc and still got better mileage than a 75mph highway cruise.

 

[TonyD]

The lower the rpm, regardless of speed, the better the mileage is. Simple as that.

Yes and no... there is a sweet spot where engine rpm, load, drag etc all come together to yield the best mpg.

 

[FK8_K20c1]

My car does 29.4MPG, I use the car M-F to go to work and that includes 79mph on average cruising on the Interstate for about 20min then once I my exit I do 65mph for 10min and then I do 35-50mph for 15min until my destination shifting at about 3,000rpms.

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